Support for TFVC roots not corresponding to the project base directory

Currently, the TFVC part of the plugin doesn’t support TFVC roots being outside of the project base directory (be it multiple roots inside of one project, or just a single root not in the default directory).

There’re some calls to project.getBaseDir() and e.g. CommandUtils.getPartialWorkspace(Project) in our code base, which doesn’t work well with multiple VCS roots (the VCS plugin in unable to perform the basic operations for such projects).

We’ll need to change that part to address the issue, and make the plugin to rely on registered VCS roots instead of touching project.getBaseDir().

This, in turn, may cause problems like #367.

Probably this will require us to enhance workfold command speed, or somehow utilize TfvcRootCache for it, because otherwise enumerating all registered VCS roots could require us to perform a lot of synchronous work (to scan for VCS roots, IntelliJ may call workfold on every item in the project directory; without an umbrella-like cache such as one in TfvcRootCache this could take too much time).

[erythana]

@ForNeVeR Sorry for pinging but just wondering, any news on this? 💯

[ForNeVeR]

Thanks, I have updated the issue title and initial post body to accomodate that case better.