IVS-629 - Ignore case matching usernames

[rw-bsi]

Prevents duplicate user accounts (eg. user@.... and User@.... are now treated as the same)

[civilx64]

A couple of notes for consideration:

1. are there any performance implications from case-insensitive searches where an index in the DB would be helpful?
2. Can you add a unit test for this? Maybe change the credentials in one file to rOOt:root?

[rw-bsi]

Thanks @civilx64

are there any performance implications from case-insensitive searches where an index in the DB would be helpful?

Will have a look - this username field is default Django so not sure a case-insensitive index already exists (if not, I'll add one)

Can you add a unit test for this? Maybe change the credentials in one file to rOOt:root?

We haven't changed Django Admin users behaviour, only the Entra ID <> Django mapping.
Django default is to treat root and rOOt as different users (in Django Admin, in API, etc...)
I can add a test for the former though.