feat: unfold commands

[acheronfail]

This PR adds in the extra command AutoFoldCode: Unfold All Open Files. Sublime Text already has a command to unfold the current file, so we don't need to implement that command.

Also, this updates the AutoFoldCode: Clear All command, so that it unfolds all folded regions in all open views as well (before it would just clear the cache, and if you ran Clear All without unfolding the regions then it would re-cache the folded regions).

It also make some changes to the code:

• All non-exported functions are prefixed with _
  • This is to make the code clearer, we want plugin_loaded to be exported, but none of the other functions need to be exported. So, since they're file-specific, why not make the code clear and reflect that?
• Restructured the source code for clarity
  • This groups the window commands together, and moves the helpers to the bottom. Why not make the source code easier to understand and read?
• Other bug fixes:
  • If there were no folded regions and the user saved, then AutoFoldCode would not update its cache.
  • A error would be thrown if some commands were executed without there being an active view in a window.
  • Fixed an error when plugin_loaded is called when there are unnamed views (like Find Results, etc)

[Vasily-X]

Nice update @acheronfail. I'll add you as a collaborator so you can keep updating this. ;)

[acheronfail]

Thanks @RIDE-2DAY, really appreciate that! 😄

I'll make sure this is fully tested, and then publish a new release of it. 👍