Refactor the post preview html to use the ViewComponent framework. This
lets us encapsulate all the HTML, CSS, and helper methods for a UI
component in a single place.
See https://viewcomponent.org.
Rename the following post replacement attributes:
* file_size_was -> old_file_size
* file_ext_was -> old_file_ext
* image_width_was -> old_image_width
* image_height_was -> old_image_height
* md5_was -> old_md5
In Rails 6.1, having attributes named `file_size` and `file_size_was` on
the same model breaks things because it conflicts with Rails' dirty
attribute tracking.
Also remove options to configure names of wiki notice pages. These names
generally don't need to be changed and we already hardcode links to wiki
pages in other places anyway.
* Adds a "Tags" field to the post replacement dialog box. The given tags
are added to the post after replacement.
* Prefills the Tags field with certain tags that usually need to be
removed after replacement: replaceme, image_sample, jpeg_artifacts, etc.
Adds a "Final Source" field to the post replacement dialog. If
specified, the post's source field will be changed to this value after
replacement.
This makes fixing the source back to the HTML page after
replacement easier.