Amend names of <molecule_chembl_id> and <parent_molecule_chembl_id> fields in API endpoints to be consistent throughout

[FionaEBI]

There is some variation in names of fields between the different API endpoints. I would like to see identical field names across all API endpoints - preferable something clear and sensible like <molecule_chembl_id> and <parent_molecule_chembl_id> used throughout :

See e.g.
<molecule_chembl_id> Mechanism/ API
<parent_molecule_chembl_id> Mechanism API
<molecule_chembl_id> Molecule API
<parent_chembl_id> Molecule API
<molecule_chembl_id> Drug Indication API
<parent_molecule_chembl_id> Drug Indication API
<molecule_chembl_id> Drug API (only - no ‘parent_molecule_chembl_id’)