We should be using the new name for the enum value instead
of the old one in the enum class docstring.
Move the old compatible name to an extra note
"Available as ``xx.yy`` in older QGIS releases."
Fixes#49171
sip6 converts all enums to python Enums, but ONLY creates
Enums with IntFlags types when the c++ type is an enum class : int.
Accordingly we need to patch back in all the operations which treat
enum values as ints, like |, &, bool, etc.
The long term solution here is to move all our c++ enums to enum
class, but that's not always straightforward and can break API
for plugins if it involves the signature of virtual methods.
