2021-07-07 Lbcom v33r0

This version uses LHCb v53r0, Gaudi v36r0 and LCG 100 with ROOT 6.24.00.

This version is released on master branch. Built relative to Lbcom v32r2, with the following changes:

Code cleanups and changes to tests modernisation cleanup testing

• Build | Rewrite CMake configuration in "modern CMake", !551 (@clemenci)