[Feature Request] Update-Check / Auto-Update

[AedDev]

Use GitHub Releases to check for updates. If there's a new version available, ask the user if the update should be downloaded. Updates should utilize a separate, small executable.

Execution order:

1. Check for updates
2. Ask user
3. Run updater as separate process
4. Close BetterRaid process
5. [Updater] Moves current version from BetterRaid to (e.g.) BetterRaid_0.0.2-alpha.bak
6. [Updater] Downloads latest version
7. [Updater] (Linux) Sets executable flag
8. [Updater] Starts updated BetterRaid
9. [Updater] Closes