[IMP] web: keep consistency with legacy pager

After the revamp of the pager, the Legacy Pager was broken because it
used the same SCSS file. This commit adds some BS classes on the Legacy
Pager to keep consistency between both versions while waiting for the
removal of the legacy one.

task-2733437

Part-of: odoo/odoo#82866

addons/web/static/src/legacy/xml/base.xml

@@ -290,10 +290,11 @@
 </t>
 
 <t t-name="web.legacy.Pager" owl="1">
-    <nav class="o_pager" aria-label="Pager">
-        <span class="o_pager_counter mr-2" t-on-click.stop="">
+    <nav class="o_pager align-items-center d-flex gap-2" aria-label="Pager">
+        <span class="o_pager_counter" t-on-click.stop="">
             <input t-if="state.editing" type="text"
-                class="o_pager_value o_input"
+                class="o_pager_value o_input d-inline-block w-auto text-right"
+                size="7"
                 t-ref="autofocus"
                 t-att-value="value"
                 t-on-blur="() => { this.state.editing = false }"
@@ -301,7 +302,7 @@
                 t-on-keydown.stop="_onValueKeydown"
             />
             <span t-else=""
-                class="o_pager_value"
+                class="o_pager_value d-inline-block border-bottom border-white"
                 t-esc="value"
                 t-on-click="_onEdit"
             />
@@ -311,7 +312,7 @@
         <span class="btn-group" aria-atomic="true">
             <!-- accesskeys not wanted in X2Many widgets -->
             <button type="button"
-                class="fa fa-chevron-left btn btn-secondary o_pager_previous rounded-left"
+                class="fa fa-chevron-left px-2 btn btn-secondary o_pager_previous rounded-left"
                 t-att-disabled="state.disabled || singlePage"
                 t-att-accesskey="props.withAccessKey ? 'p' : false"
                 aria-label="Previous page"
@@ -320,7 +321,7 @@
                 t-on-click="ev => this._changeSelection(-1, ev)"
             />
             <button type="button"
-                class="fa fa-chevron-right btn btn-secondary o_pager_next rounded-right"
+                class="fa fa-chevron-right px-2 btn btn-secondary o_pager_next rounded-right"
                 t-att-disabled="state.disabled || singlePage"
                 t-att-accesskey="props.withAccessKey ? 'n' : false"
                 aria-label="Next page"