Add fields to RawBlame RPC for markUnblamableLines and markIgnoredLines
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Add `mark_unblamable_lines` and `mark_ignored_lines` fields to the RawBlame RPC to allow gitaly to pass the `blame.markUnblamableLines` and `blame.markIgnoredLines` configuration parameters to the blame command.
For example we want to facilitate something like:
```
git -c blame.markUnblamableLines=true -c blame.markIgnoredLines=true blame README.md --ignore-revs-file .git-blame-ignore-revs -p
```
issue