Add comments related to ATLASRECTS-5130
Add comments related to https://its.cern.ch/jira/browse/ATLASRECTS-5130
- Add description of std::enable_shared_from_this to PixelDiodeMatrix.h
- Add owner information.
- Remove inappropriate copyright statement.
Add comments related to https://its.cern.ch/jira/browse/ATLASRECTS-5130