FR: blame view for a diff

[vt-alt]

Sometimes (for example when porting) it's useful to see a blame view for a diff output. It could be cool if tig supports this mode.

Also, this could be useful in commit view -- if user will be able to toggle viewing commit diff and blamed commit diff.

[adlai]

I was first going to respond that this request is illogical, because git-blame only works on individual commits; however, after further consideration of what you might have intended, I think you're referring to diffs between ranges of commits, where the blame output is nontrivial... however, it is probably better implemented first as an extension to git-blame rather than glued onto tig.

[vt-alt]

Benefit of tig is that we would conveniently scroll-and-view related commits in TUI (the way similar to tig blame). If implementing blamed diff logic is too complicated for tig (it's implemented in numerous other scripts, though), alternative would be to allow tig to view pre-geenrated blamed diff output (in a view similar to tig blame). Integrated diffing would be better than just pre-generated diff viewer because , key could work and that key is super useful.