Bump Protocol to v19.2.0 and add l10n for Klar (Focus) branding

[janbrasna]

One-line summary

Enables l10n for Focus screenshot on landing page, and locally adds a missing class for the wordmark via Protocol update.

Significant changes and points to review

• Updates Protocol to v19.2.0

Issue / Bugzilla link

Fixes #14489

Testing

(either make build or make preflight depending on how you manage deps)
http://localhost:8000//de/firefox/browsers/mobile/focus/
http://localhost:8000/de/firefox/browsers/mobile/

[janbrasna]

Notes for reviewer:

[janbrasna]

I have left the default imgs in their original location too for now, but wondering what's the best practice? Remove them and keep only in l10/en-US? (I'd ideally symlink them, from img/l10n/en-US/* to img/firefox/browsers/*, but not sure how the tooling likes that…)

EDIT: removed for now, git tracks that as rename/mv, it's just not obvious in the nonl10n folder there's the last screenshot elsewhere in l10n media, but that's as designed… 🤷

[reemhamz]

Fwiw, pages that switch out images best on language should have said images in the /img/l10n so the back-end logic switches them out, so you correctly placed them here 👍🏼

[reemhamz]

Thank you for bringing this to light!!!
I think the best course of action would be to make this change in Protocol itself, and I managed to do that to save you some time 👍🏼 Once that gets reviewed and merged, we can update this PR to use the updated version of Protocol and have Firefox Klar's wordmark be usable :)

I suggest you convert this PR to draft for now, and we can update it when the Protocol changes come in.

[reemhamz]

This PR is just waiting on the new Protocol version, set to publish soon: mozilla/protocol#937

[reemhamz]

The Protocol bump we've been waiting on is almost merged to Bedrock! Once that's done, feel free to continue on with this change :D

For now, I'm going to remove the "Needs Review" label. @janbrasna go ahead and add back the label once this PR finished :)

[reemhamz]

Thanks for your patience in waiting for the new Protocol version to get published!

I reviewed your work, and well done! This looks like it's good to go. r+ 🍉

[reemhamz]

Fwiw, pages that switch out images best on language should have said images in the /img/l10n so the back-end logic switches them out, so you correctly placed them here 👍🏼