Retroactively unify inconsistent spelling of language, editor and OS names

[muety]

1. Extend "canonical names" concept that was begun in Duplicate entries in language-specific leaderboard #784 to editors and OS' and add more rules
   • Apply canonical name if defined (e.g. vscode -> VSCode)
   • Otherwise capitalize entity name
2. Write migration to retroactively update all heartbeats, durations and summary items (🫨)

Also relates to #737, #647, #418, #313, #234