Add native translation support based on the Translator API

[tomayac]

• Fixes Language Translator #2863
• Fixes [APP-438] In-app translation #404
• Fixes Bluesky should support inline translations via DeepL #1327
• Fixes Translation of post should be in app #7427
• Fixes Integrate translation directly into de app #5077

This PR adds native translation support based on the Translator API that shipped in Chrome 138 as a progressive enhancement. On non-supporting browsers, the current behavior of linking to Google Translate is maintained.

The original post from the examples below was written in English and translated to German.

Translating a post with the Translate button

This shows the translation in lieu of the original text, with the option to toggle back to the original.

Translating a post with the Translate post menu item:

This opens a modal dialog with the translation.

Translating a direct message with the Translate message menu item:

Since this all happens on the client-side, this is a huge privacy win, and compatible with end-to-end encrypted DMs.

[tomayac]

FYI @mozzius who seems to have touched the translation hook recently.

[tomayac]

@mozzius Made the linter happy, so the next time you (someone) approves the workflows to run, it should hopefully be all green. Anything else I could do to make this move forward?