Improve RTL support; add automation to install {{int:lang}} system
Makes RTL tweaks to:
- Table headings
- Checkboxes for the projects of the intake form
- Padding around the 'Cancel' link in the intake form
Note that the changes to DeployCommand depend on https://gerrit.wikimedia.org/r/c/mediawiki/core/+/1050038
Bug: T368578