variants(h5): add generic H523R(C-E)T, C533RET and Nucleo-H533RE

[fpistm]

Fixes #3062.

[albantor30]

Hello, I was going to work on adding this Nucleo board when I saw that is was already done, great! However, I'm wondering if this PR should not also add variant_NUCLEO_H533RE.cpp to CMakeLists.txt (and update boards_db.cmake)? Or maybe it is going to be automatically added later on?
I take the opportunity to thank @fpistm for all the good work!

[fpistm]

Thanks @albantor30 .
Di not hesitate to give your feedback on this PR.

[fpistm]

I take the opportunity to thank @fpistm for all the good work!

Thanks! 😉