reorder nav (sidebar) imports so that hooks can still override them (#7954)

- main_nav_css & main_nav_js were added when the new slim sidebar was being built
- with the legacy styles/js - there was little risk of there being conflicts
- with the new sidebar CSS, this sidebar bundle comes with a large duplicate of what is in core.css so we should add it before the hooks run so that hook scan override if needed as per our documentation
- this is a temporary fix for #7943 - ideally we should avoid sidebar.scss bundle duplicating so much of the core css
- note: JS is lower risk but should follow the same convention

CHANGELOG.txt

@@ -17,6 +17,7 @@ Changelog
  * Fix: Fix issue where bulk actions would not work for object IDs greater than 999 when `USE_THOUSAND_SEPARATOR` (Dennis McGregor)
  * Fix: Set cookie for sidebar collapsed state to "SameSite: lax" (LB (Ben Johnston))
  * Fix: Prevent error on creating automatic redirects for sites with non-standard ports (Matt Westcott)
+ * Fix: Restore ability to customise admin UI colours via CSS (LB (Ben Johnston))
 
 
 2.16 (07.02.2022)

docs/releases/2.16.1.rst

@@ -18,3 +18,4 @@ Bug fixes
  * Fix issue where bulk actions would not work for object IDs greater than 999 when ``USE_THOUSAND_SEPARATOR`` (Dennis McGregor)
  * Set cookie for sidebar collapsed state to "SameSite: lax" (LB (Ben Johnston))
  * Prevent error on creating automatic redirects for sites with non-standard ports (Matt Westcott)
+ * Restore ability to customise admin UI colours via CSS (LB (Ben Johnston))

wagtail/admin/templates/wagtailadmin/admin_base.html

@@ -5,10 +5,11 @@
     <link rel="stylesheet" href="{% versioned_static 'wagtailadmin/css/vendor/jquery-ui/jquery-ui-1.10.3.verdant.css' %}" />
     <link rel="stylesheet" href="{% versioned_static 'wagtailadmin/css/vendor/jquery.tagit.css' %}">
     <link rel="stylesheet" href="{% versioned_static 'wagtailadmin/css/core.css' %}" type="text/css" />
-    {% hook_output 'insert_global_admin_css' %}
 
     {% main_nav_css %}
 
+    {% hook_output 'insert_global_admin_css' %}
+
     {% block extra_css %}{% endblock %}
 {% endblock %}
 
@@ -52,11 +53,10 @@
     <script src="{% versioned_static 'wagtailadmin/js/core.js' %}"></script>
     <script src="{% versioned_static 'wagtailadmin/js/vendor.js' %}"></script>
     <script src="{% versioned_static 'wagtailadmin/js/wagtailadmin.js' %}"></script>
-    {% hook_output 'insert_global_admin_js' %}
-
-
 
     {% main_nav_js %}
 
+    {% hook_output 'insert_global_admin_js' %}
+
     {% block extra_js %}{% endblock %}
 {% endblock %}