[Feature Request]Add an option to choose Offline Mode

[SKPloft]

Problems

VRCFT would initial module libs from github, and check if there's any update, for users have connection problems to github, this method would cause installed module loading with slow speed, log below:

Suggest

Adding an option in the setting to choose Offline Mode would help this, expected behavior below:

[SKPloft]

noticed this issue is similar to #208 , I will mark this here