Add breadcrumbs support across application (#1897)

* Add breadcrumbs support across application

Fixes #1896

* Potential fix for tests

* Simplify breadcrumbs implementation

Remove complex breadcrumbs logic from controllers and concern, replacing with a simpler default approach that sets a basic breadcrumb based on the current controller name

* Refactor page header and breadcrumbs rendering

Remove complex breadcrumbs helper method and update layout to use more flexible content_for approach for page headers and breadcrumbs

* Add fallback breadcrumbs rendering to settings layout

app/controllers/concerns/breadcrumbable.rb

@@ -0,0 +1,13 @@
+module Breadcrumbable
+  extend ActiveSupport::Concern
+
+  included do
+    before_action :set_breadcrumbs
+  end
+
+  private
+    # The default, unless specific controller or action explicitly overrides
+    def set_breadcrumbs
+      @breadcrumbs = [ [ "Home", root_path ], [ controller_name.titleize, nil ] ]
+    end
+end