requireAllDefinedDependencies: avoid running the same transform many times

[jjohannes]

With the current approach, the input to the transformation is different for each subproject due to different classpaths this leads to the transformation running multiple times producing multiple Jar files (with the same content). If we always give the metadata for all defined dependencies that shall be patched as input, the input should be the same as long as all subproject use the same plugin configuration.

It basically means that we should return the full list here instead of filtering it based on the current projects classpaths.