Reevaluate submissions by programming language

[prandla]

Our fork has buttons like this:

I feel like these are probably more useful for us than anyone else, as we tend to give python submissions more special treatment so it's sometimes useful to regrade all python submissions. But maybe it could be useful for others too.

[veluca93]

I don't think there are reasons not to add those, but otoh I also don't think there are strong reasons to :-)

[pxsit]

I think it would be even more useful for "Reevaluate Full score/ Partial Subtask"