Make Support Theme ready for Rosetta forums

[SergeyBiryukov]

Most of the theme i18n should already be done in #2151, let's use this ticket for any additional changes.

The following tickets should be fixed before the launch:

#2396

Create a translation project for the new Support Theme

#2398

Support Theme: List of inline topic actions is too long when translated

#2450

Forums: Search doesn't work with the new theme on Rosetta forums

#2473

Forums: Activate "Logged Out Admin Bar" on Rosetta forums

[SergeyBiryukov]

#2398 is not a blocker, but #2450 is.

[SergeyBiryukov]

@samuelsidler: I think the theme is ready for Rosetta forums, what are the next steps?

[samuelsidler]

Talked with @SergeyBiryukov about this. We're going to do the following:

1. Switch ru.wordpress.org/support/ to the new theme (already done).
2. Post on make/polyglots about the change and ask for volunteers. This will also serve as a notification to translate the new theme.
3. Switch a few more locales to the new theme, based on the above.
4. Double check RTL before switching any RTL locales.
5. Switch all locales en masse.

[SergeyBiryukov]

In 5041:

Support Theme: Use correct arrow color for active "Support" menu item on Rosetta sites.

See #2395.

[SergeyBiryukov]

In 5644:

Support Theme: Adjust styles for proper RTL support.

Fixes #2395.