Option to ignore whitespace in blame view
### Problem to solve
Blame view should have the option to ignore white space (`git blame -w`).
### Further details
In diff view, there is the option to ignore white space changes (via UI button and URL suffix `?w=1`). However, there seems to be no such option in Blame view.
### Proposal
Add option to ignore white-space to Blame view. This could look exactly the same as in Diff view and also work with the same URL parameter `?w=1`.
### Links / references
I found an old issue gitlab-ce#5951, but as this has been closed with no apparent resolution, I am opening a new one.
issue