* merge `CheckLFSVersion` into `InitFull` (renamed from `InitWithSyncOnce`)
* remove the `Once` during git init, no data-race now
* for doctor sub-commands, `InitFull` should only be called in initialization stage
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>