Leaderboard Improvements

[Keywarn]

• [x] Spelling mistake
• [x] UX can be confusing if the player submits and then clicks leaderboard straight away - should maybe grey out the leaderboard button until submitted or refresh the leaderboard if new data is submitted
• [ ] Proper error reporting in some kind of modal (can we make this generic? string, yes callback, no callback - disable buttons if no callback)
• [ ] Loading widget and bring the board down before it has loaded
• [ ] See the board without completing a run [do we need this?]
• [ ] Leaderboard on website [later when we have a site - needs new item]
• [x] Autofill username
• [ ] Allow for porting usernames [after auth]
• [x] Highlight your name