Achievements: Fix leaderboard headers and selection focus

[SternXD]

Description of Changes

Fixes #13141 When in some languages it would overlap rank and name in the leaderboard menu. And focuses the last item the user clicked instead of going to the top.

Rationale behind Changes

• Long translations didn’t fit the old rank column, causing clipping/overlap.
• Remembering selection only when returning from a leaderboard makes browsing smoother

Suggested Testing Steps

• Open a game with leaderboards (e.g., Burnout 3) and view the leaderboard list in a language with longer strings (Italian).
• Check that headers (“Posizione”, “Nome”, etc.) are centered and not overlapping, and rows align under each heading.
• Go into a leaderboard, then back out (to the leaderboard menu if there's multiple leaderboards for the game you are playing) make sure the selection stays on the previously opened leaderboard and the list doesn’t jump.

Did you use AI to help find, test, or implement this issue or feature?

No.

[bigol83]

i can confirm it works perfectly fine 🎉

[kamfretoz]

LGTM