eeschema cpp files consume generated header files that have targets in
the common directory, so no dependencies get created from eeschema. We
add the dependencies in common to force the setting through libraries.
Fixes: lp:1831643
* https://bugs.launchpad.net/kicad/+bug/1831643
Building custom targets that depend on custom commands such as our
keyword lexer requires two layers of indirection to pick up changes
properly and not overwrite the same file in parallel builds.
Fixes: lp:1831643
* https://bugs.launchpad.net/kicad/+bug/1831643