[2.1.0 GUI] Autoupdater, small improvements

• Added an opt-in autoupdater and version checker
  • There will now be a button to check for updates. By default for privacy, new versions are only searched when clicking on this button, but you can enable automatically searching for new updates in the settings.
  • If a new update is available, SAC will propose to use the autoupdater, copy the release url, or dismiss.
  • The autoupdater is not included in SAC and will be downloaded when updating. It will be downloaded from GitHub from the autoupdater branch here.
• Selecting a folder will now automatically fill its name into the AppID / Name field (as suggested in #63 - thanks to @lolinator53 for #64)
• When a web request fails, it will now update the main window to properly display logs
• Prevented other windows (like Settings or Crack selection) from being resized

NOTE: Deleting the config file isn't required, and shouldn't be required in the future as well. SAC will always try to update the config file to make it compatible.

SteamAutoCracker GUI requires a 64 bits Windows computer.