Use repopath instead of projectpath in module-definitions

This is a subtask for #2.

While the module-definitions definitely needs cleanup, in here I did not touched anything but replaced references by projectpath to repopath. In cases where modules were already covered by repopath glob, removed them so they are not duplicated. In places where the reference is the glob rather than the leaf, I used /* to make it obvious.

CC: @aacid @nicolasfella @bcooksley @sitter