Adds command (compare, copy sha/message, etc) support to git diff split view
Fixes #41 - Toggle Blame annotations on compare files page

- Status bar blame information will hide
  - CodeLens change to a `Cannot determine...` message and become unclickable
  - Many menu choices and commands will hide
Fixes #36 - Blame information is invalid when a file has unsaved changes
Fixed #38 - Toggle Blame Annotation button shows even when it isn't valid
Preps v2.9.0

Adds data formatting option to blame annotations
Preps v2.8.2

Adds originalFilename support to git-log enrichment

Renames current Open File command to  Open Working File
Renames current Open Files command to  Open Working Files
Adds new Open File command to open the commit version of the file
Adds new Open Files command to open the commit version of the files

Fixes #33 - commit messages needs to be escaped

Adds status info to commit details quick pick

Changes Show Previous Commit History to Show Previous File History

Adds clipboard copy message to commit files quick pick list