Ensure filesystem permissions are handled correctly

[Kade-N]

In particular, when the Launcher requests admin to apply compatibility fixes, this can result in a case where LK's folders are protected and cannot be accessed when non-admin, resulting in "unauthorized access exception" or undefined behaviour if this exception is not caught

Should check over all cases where LK needs admin, and try to avoid executing code as admin when not needed to avoid this - or just fix the filesystem permissions in code

[Kade-N]

Related, 3dc3eac changes the behaviour of the updater - previously, it would always re-launch whatever LK app triggered the updater, which is good UX but created a problem where the game would run as admin. Now, if the app to re-launch is the ModAPI Launcher, it will instead only show a message telling users to manually launch the game