usernames should be queried case insensitive

[butonic]

➜  core git:(testFixOCISPR409) ✗ micro call com.owncloud.api.accounts AccountsService.ListAccounts "{\"query\":\"on_premises_sam_account_name eq 'Alice' or mail eq 'Alice'\"}"{        "accounts": [
                {
                        "id": "Alice",
                        "account_enabled": true,
                        "display_name": "Alice Hansen",
                        "preferred_name": "Alice",
                        "mail": "alice@example.org",
                        "password_profile": {},
                        "on_premises_sam_account_name": "Alice"                }        ]}
➜  core git:(testFixOCISPR409) ✗ micro call com.owncloud.api.accounts AccountsService.ListAccounts "{\"query\":\"on_premises_sam_account_name eq 'alice' or mail eq 'alice'\"}"
{}

[phil-davis]

FYI usernames are not case-sensitive in oC10 at all. You can create user Alice and then do API calls to see files, share files,... and refer to the user as Alice alice ALICE ... and modify/delete the user using any mixed-case.

The various OCIS implementations of APIs need to do the same, otherwise we can end up with users Alice alice and ALICE and plenty of confusion when they share resources...

[butonic]

there is a difference between username and userid. while usernames are not case sensitive, userids are. I need to fix this pr before we will see the implications for the test suite.