Derive PatchComponent from RecordComponent

[franzpoeschel]

PatchRecordComponent uselessly duplicates lots of logic from RecordComponent and lots of functionality from RecordComponent is missing in ParticlePatches, e.g. selective chunk loading. This is crucial in streaming setups where loading the entire particle patches information results in NxM communication patterns.

TODO:

• BaseRecordComponent is now useless and can be merged with RecordComponent Keeping them separate for now keeps the diff smaller
• Alternatively, move a large part of the RecordComponent logic to BaseRecordComponent and keep only those parts in RecordComponent that really should not be part of PatchRecordComponent That separation would imply having to separate the flush/read logic again.

[ax3l]

Nice! Looks great (incl Python update).