[FIX] web: correctly align column values with column header

Steps to reproduce:
- Install planning app.
- Go to planning app, and convert the view to List.
- Group by Resource -for example-.
- Notice how the allocated time values are mis-aligned with the header label.

Investigation:
- in the planning tree view, notice the property `open_form_view` set to `True` https://github.com/odoo/enterprise/blob/418ea2114c7d935865dc52e5fd5a30d626987190/planning/views/planning_views.xml#L8
- In the `getGroupNameCellColSpan` method:
	- the `firstAggregateIndex` is `1` belonging to the `allocated_hours` (Allocated Time)column which set the `colspan = firstAggregateIndex = 1`
	- as `this.hasSelectors` is `true`, `colspan = colspan+1 = 2` (which is the correct value)
	- but now as the `open_form_view` was set to `True`, the `this.props.onOpenFormView` exists and so the `colspan = colspan+1 = 3` which makes the value be misaligned to the right by one column.

The proposed fix:
- As the `open_form_view` option add a View button to the end of the row, it makes sense to do the check with the `lastAggregateIndex` inside `getGroupPagerCellColspan` method.
- In our case:
	- the `lastAggregateIndex` is `1` belonging also to the `allocated_hours` which set the `colspan = this.state.columns.length - lastAggregateIndex - 1 = 3 - 1 - 1 = 1`
	- as we don't display optional fields this check fails https://github.com/odoo/odoo/blob/5af3cfc2b9ce648ae4aff69150266e4ad519050d/addons/web/static/src/views/list/list_renderer.js#L1025-L1027 and the `colspan = 1`
	- Now we check the `this.props.onOpenFormView` condition which set `colspan = colspan+1 = 2` which is correct.
- But what if we wanted to show the optional field `allocated_percentage` would this fix still work? Yes!
	- the `lastAggregateIndex` is `2` belonging to the `allocated_percentage` which set the `colspan = this.state.columns.length - lastAggregateIndex - 1 = 3 - 2 - 1 = 0`
	- as we do display an optional fields= this check works https://github.com/odoo/odoo/blob/5af3cfc2b9ce648ae4aff69150266e4ad519050d/addons/web/static/src/views/list/list_renderer.js#L1025-L1027 and the `colspan = colspan+1 = 2`
	- Now we check the `this.props.onOpenFormView` condition which set `colspan = colspan+1 = 3` which is correct.
- One last case, what if we have no aggregates
	- both firstAggregateIndex` = `lastAggregateIndex` = -1
	- we go into the else clause inside `getGroupPagerCellColspan`, making the `colspan = this.state.columns.length > 1 ? DEFAULT_GROUP_PAGER_COLSPAN : 0 = True ? DEFAULT_GROUP_PAGER_COLSPAN : 0 = DEFAULT_GROUP_PAGER_COLSPAN = 1
	- if the `open_form_view` was `True`, the colspan becomes `colspan = colspan+1 = 2`.

opw-3764616

closes odoo/odoo#156647

Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

addons/web/static/src/views/list/list_renderer.js

@@ -1012,23 +1012,24 @@ export class ListRenderer extends Component {
         if (this.hasSelectors) {
             colspan++;
         }
-        if (this.props.onOpenFormView) {
-            colspan++;
-        }
         return colspan;
     }
 
     getGroupPagerCellColspan(group) {
         const lastAggregateIndex = this.getLastAggregateIndex(group);
+        let colspan;
         if (lastAggregateIndex > -1) {
-            let colspan = this.state.columns.length - lastAggregateIndex - 1;
+            colspan = this.state.columns.length - lastAggregateIndex - 1;
             if (this.displayOptionalFields) {
                 colspan++;
             }
-            return colspan;
         } else {
-            return this.state.columns.length > 1 ? DEFAULT_GROUP_PAGER_COLSPAN : 0;
+            colspan = this.state.columns.length > 1 ? DEFAULT_GROUP_PAGER_COLSPAN : 0;
         }
+        if (this.props.onOpenFormView) {
+            colspan++;
+        }
+        return colspan
     }
 
     getGroupPagerProps(group) {

addons/web/static/tests/views/list_view_tests.js

@@ -2141,6 +2141,60 @@ QUnit.module("Views", (hooks) => {
         }
     );
 
+    QUnit.test(
+        "basic grouped list rendering 4 cols with aggregates, selector and openFormView",
+        async function (assert) {
+            await makeView({
+                type: "list",
+                resModel: "foo",
+                serverData,
+                arch: `
+                    <tree open_form_view="True">
+                        <field name="datetime"/>
+                        <field name="int_field" sum="Sum1"/>
+                        <field name="bar"/>
+                        <field name="qux" sum="Sum2" optional="hide"/>
+                    </tree>`,
+                groupBy: ["bar"],
+            });
+
+            assert.strictEqual(
+                target.querySelector(".o_group_header th").getAttribute("colspan"), "2"
+            );
+            assert.strictEqual(
+                target.querySelector(".o_group_header th:last-child").getAttribute("colspan"),
+                "2",
+            );
+        }
+    );
+
+    QUnit.test(
+        "basic grouped list rendering 4 cols with aggregates, selector, optional and openFormView",
+        async function (assert) {
+            await makeView({
+                type: "list",
+                resModel: "foo",
+                serverData,
+                arch: `
+                    <tree open_form_view="True">
+                        <field name="datetime"/>
+                        <field name="int_field" sum="Sum1"/>
+                        <field name="bar"/>
+                        <field name="qux" sum="Sum2" optional="show"/>
+                    </tree>`,
+                groupBy: ["bar"],
+            });
+
+            assert.strictEqual(
+                target.querySelector(".o_group_header th").getAttribute("colspan"), "2"
+            );
+            assert.strictEqual(
+                target.querySelector(".o_group_header th:last-child").getAttribute("colspan"),
+                "1",
+            );
+        }
+    );
+
     QUnit.test("group a list view with the aggregable field 'value'", async function (assert) {
         serverData.models.foo.fields.value = {
             string: "Value",