Upgrading of generics with recursion

Following on from [this commit](https://github.com/BHoM/Versioning_Toolkit/pull/185/commits/420af0648bfb18435368fde8d1f09f54f6cf3ccb) as part of [this PR](https://github.com/BHoM/Versioning_Toolkit/pull/185), we need to strengthen up the Versioning for Generics. The implementation in the commit sufficed for the use case which was holding up several toolkits, so decision to merge as was, and raise this issue for future work (future being this milestone and not too far in the future) was agreed. This is the issue to capture that.