Role selector Mobile Updates

[Kodylow]

Makes several changes to the Role Selector page:

Old:

New:

1. Updates to copy:

• Change to "Welcome, Guardian" to avoid stacking big "Fedimint" and make it easier to fit title on mobile screen
• Setup Leader: slarifies that it's just for setup, not a difference among guardians
• Follower: Clarifies their role as after setup leader and that that's when the actual federation gets set up.
• Removes mainnet warning: we should do the mainnet warnings on the leader configuration page if they actually select mainnet, not preemptively. Also tells ppl to file issues with us.

2. Moves warning below role selector, above next button:

• On mobile the big warning pushes the follower option below the fold, this looks and makes it more like an "acknowledge by clicking next"

3. Fixes mobile UI layout

• Fixes overflows in radiobuttongroup children
• centers header on mobile (will be centered across all mobile pages)
• 100% width for next button

[Kodylow]

I don't like the "Are you creating a federation or joining one" at all, it just seems unnecessary especially since the creating or joining aren't easily visually mapped to setup vs guardian from that position, I think we should drop it

[wbobeirne]

Some small code notes in here.

I'm not sure how we want to come to consensus around copy changes. For the most part I agree with the idea behind these changes, but it's going to get hard to decide a source of truth for copy if we start calling audibles in PRs.

I'm pretty ok with these but want to give a sec for others to weigh in.

[wbobeirne]

If you update existing keys in english, you need a way to make sure they get re-translated for other languages, otherwise there'll be a mismatch. This either means doing the translation yourself, or removing the keys to allow them to be re-translated later.

I don't love the way this works right now, and I'm open to alternative approaches if anyone's got ideas.

[Kodylow]

fixed and translated w google, will wait on what others say about how to update copy, I'll just add these as comments on figma