Site Selector: Add Comments Translation (and alphabeticise)

[Aurorum]

Addresses https://github.com/Automattic/wp-calypso/pull/86633#discussion_r1465618185

Proposed Changes

Just add Comments to the Site Selector since it was missed in #86633. The list is becoming a bit unwieldy too, and I thought it could do with some alphabetisation. Happy to remove if it'd be easier to review though.

Testing Instructions

Go to /comments in a language other than English.

Before:

After:

cc @simison

[sixhours]

👋 Hi hi! Can you give this a rebase and I'll take another look? Thank you @Aurorum!

[Aurorum]

All done! Thanks for giving these PRs a look!! :)