Details: Refactor the git command to be able to run a batch. Run diff and diff --cached in a batch

Details:  - Conform to conventions.

Details:  - To make it conform to naming convention.

Fixes: Make git diff work for staged files, do not launch submit if file list empty, make file  model read only, add conveniences

Details: Add a type data field to the git file model

Details: Move routine to get project file list into VCSBase, use it in p4 and git to filter submit lists.

Details: Execute git status from repo directory

Task: 205821
RevBy: con
Details:  Add a IVersionControl to git. Extend IF to able to return a name and add enabling options. Connect project explorer to enable the right VCS.

With many git commands it is safer to disambiguate files from refs by
putting '--' in front of the list of files.

Also corrected a margin in the git submit panel.