Resources requested by macros should be rendered in exports and notifications and other situations

CONF-7409 was implemented for Confluence 2.8, allowing macros to use #requireResource (or WebResourceManager.requireResource()) to declare which CSS and JS resources they required when the page was built.

This functionality doesn't currently extend to including these resources in the following situations:

preview in the editor: need to get the resources via AJAX from the server and include them in the page dynamically (see CONF-11982)

• exports and notifications: use a hard-coded list of resources generated by /styles/combined.css?forWysiwyg=true
• rich-text editor (potentially): uses same hard-coded list as exports and notifications.

(The rich-text editor is less important because only Confluence macros typically render content that needs to be styled there. Most just appear as {macro}...{macro}.)