Overhaul AssemblyNameRegex

[bddckr]

AssemblyNameRegex in the FodyWeavers.xml files should be restricting the assemblies the particular configuration file affects.

Currently the setting just gets merged across files, but it makes more sense to allow setting all settings, including the list of weavers to run for specific assemblies. This allows a library component to use Malimbe (configured with the library's settings) while also allowing any user of that library to use Malimbe with different settings.

Perhaps AssemblyNameRegex should move into the root-level element Weavers instead? This would need to still allow specifying multiple assemblies, which should be easily possible since it's treated as a regex after all.