Reinclude functionality to enumerate unenumerated stereoisomers

[althea-hansel]

• Added function for enumerating unenumerated stereoisomers
• Function runs after acid/base and tautomerization, so will be performed on resulting acid/base and tautomer derivatives of initial molecule
• Default capped at generation of 32 isomers per mol

Manual testing performed with attached Jupyter notebook
enumerate_unassigned_stereoisomers_example.ipynb.gz

[althea-hansel]

Noticed that scrubber fails to enumerate the variants of wh9:

c1cc(ccc1CN2CCC(CC2)N3c4cc(c(cc4NC3=O)Cl)Cl)Cl

Have not found source of issue

[diogomart]

Summary of brief meeting to tackle this issue
Here's a link to not ported and currently private code that implements such amine flips
For amines with three unique/different substituents, enumerate individual molecules, like for stereo isomers.
For amines with symmetric substituents but that are part of a ring subjected to ring flips, enumerate both amine conformers as part of ringfixes.