Explorer: use files.exclude for filterToAddRemovedOnWorkspacePath

[bpasero]

There is the last remaining toWorkspaceRelativePath being used in explorer to filter out events on version control folders. Instead of this hardcoded check I suggest to simply read files.exclude and ignore file events from paths that match any of the excludes. Since this check is about updating the explorer it makes sense to ignore file events for paths that are hidden anyways.

[isidorn]

@bpasero please review, I have tried it out and seems to wokr fine. Once you give me the thumbs up I will trigger new builds

[bpasero]

@isidorn you might want to add some steps for how to verify this, it is not easy because basically you can only verify through debugging.

[isidorn]

To verify:

1. Make some changes outside of vscode and make sure the explorer picks up those changes - especially try for one of the slave roots
2. Open developer tools, add a breakpoint in explorerView doRefresh method. Make some change outside of vscode in a file that is being excluded by files.exclude setting. Verify the breakpoints is not getting hit.