Embed and setup git hooks

We have some git hooks on the wiki https://wiki.koha-community.org/wiki/Tips_and_tricks for pre-commit and pre-push. But developers need to install them manually, and it seems that they often forget (the pre-commit script on the wiki has been broken for several years and nobody noticed). I am suggesting to embed them in koha-misc4dev and to install them when the container is started.

It could be achieved using symlinks or git config --local core.hooksPath /kohadevbox/misc4dev/git_hooks. I guess the script we will embed here could test if a user git hook exists and run it if so, to let developers defined their own if they wish.