feat(log): Add key shortcut to copy commit hash

[reobin]

Something like y or c would be super useful to quickly copy the commit hash when using gitin log

I'm willing to work on this when I have some free time. In the meantime, if anyone wants to have a go at it, it's super appreciated too.

[reobin]

I understand a library will probably have to be used because copy/pasting is platform-specific, and I'm not sure we want to handle that inside gitin.

@isacikgoz Do you have a preference as to which library is to be used here? clipboard seems to be a good option even if it has not been updated in a while. There are others.

Also, please share if I'm missing something or if you have thought of another solution.

Thanks!