Make versioning consistent with Tudatpy

[DominicDirkx]

Since the documentation of tudat-space is now, and will in the future be, mainly limited to the Python interface, with C++-related issues relegated to the developer documentation, the version number of tudat-space should be set to be in line with tudatpy.

This means that

• Past version numbers should be removed or modified to be consistent with the associated tudatpy version
• The release of a new tudatpy version will always be associated with a new release (stable version) of tudat-space