[FIX] web : Fixed datetime filter search based on wrong hours

Reproduce :
(With timezone GMT+3)
- Create any record R1 with previous day's date and time after 21:00.
- Create any record R2 with today's date and time after 21:00.
- Create a filter to show all todays records (Date is between "<TODAY'S DATE> 00:00:00 and <TODAY'S DATE> 23:59:59".

Result :
  Even though R1 is in yesterday's date, it will show in the list.
  R2 will not show in this list.

Explanation :
  This behaviour has been observed in several modules, for any timezone but UTC & only with custom filters default datetime values.
  The search was applied on [datetime(UTC) + 2 * offset] because the timezone wasn't correctly set.

Solution :
  Timezone is now correctly set on default datetime values.

closes odoo/odoo#79516

X-original-commit: 6fd105b89ea30695d6a324a5aa0b2004987c2e47
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>
Signed-off-by: Onockx Audric (auon) <auon@odoo.com>

addons/web/static/src/legacy/js/control_panel/custom_filter_item.js

@@ -120,9 +120,9 @@ odoo.define('web.CustomFilterItem', function (require) {
                     }
                     break;
                 case 'datetime':
-                    condition.value = [moment('00:00:00', 'hh:mm:ss')];
+                    condition.value = [moment('00:00:00', 'hh:mm:ss').utcOffset(0, true)];
                     if (operator.symbol === 'between') {
-                        condition.value.push(moment('23:59:59', 'hh:mm:ss'));
+                        condition.value.push(moment('23:59:59', 'hh:mm:ss').utcOffset(0, true));
                     }
                     break;
                 case 'selection':

addons/web/static/tests/legacy/control_panel/custom_filter_item_tests.js

@@ -419,6 +419,45 @@ odoo.define('web.filter_menu_generator_tests', function (require) {
             cfi.destroy();
         });
 
+        QUnit.test('default custom filter datetime', async function (assert) {
+            assert.expect(5);
+
+            class MockedSearchModel extends ActionModel {
+                dispatch(method, ...args) {
+                    assert.strictEqual(method, 'createNewFilters');
+                    const domain = JSON.parse(args[0][0].domain);
+                    assert.strictEqual(domain[0][2].split(' ')[1],
+                        '04:00:00',
+                        "domain should be in UTC format");
+                    assert.strictEqual(domain[1][2].split(' ')[1],
+                        '03:59:59',
+                        "domain should be in UTC format");
+                }
+            }
+            const searchModel = new MockedSearchModel();
+            const cfi = await createComponent(CustomFilterItem, {
+                props: {
+                    fields: this.fields,
+                },
+                session: {
+                    getTZOffset() {
+                        return -240;
+                    },
+                },
+                env: { searchModel },
+            });
+
+            await toggleAddCustomFilterStandalone(cfi);
+            await testUtils.fields.editSelect(cfi.el.querySelector('.o_generator_menu_field'), 'date_time_field');
+
+            assert.strictEqual(cfi.el.querySelector('.o_generator_menu_field').value, 'date_time_field');
+            assert.strictEqual(cfi.el.querySelector('.o_generator_menu_operator').value, 'between');
+
+            await cpHelpers.applyFilter(cfi);
+
+            cfi.destroy();
+        });
+
         QUnit.test('input value parsing', async function (assert) {
             assert.expect(7);