Rename TBoundingBox None Ctor flag

[J-Meyers]

Changed apps/libraries

• Renamed flag to bounding box from None to NoFlags to prevent autogenerated stubs from conflicting with python None type

PR Description

• Fixes python typing issue where previously it tried to annotate another type to the None type in the autogenerated stub
  • This issues is particularly visible if trying to use mypy which generates an unrecoverable error (line number difference is because this was done using an older commit of mrpt)
  • The current issue effectively prevents using mypy for type checking in any projects which have any sort of transitive import of mrpt
    

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I acknowledge to have:

• Read the CONTRIBUTING page
• Updated doc/source/doxygen-docs/changelog.md to describe these changes (if applicable)
• Updated AUTHORS (if applicable)

(Notify: @MRPT/owners )

[jlblancoc]

Good point! It would be great to scan the rest of the Python wrapping code for other similar cases...