Optional user and password subscript in login Page

[minottic]

Issue Name

user and password subscript in login Page

Summary

When using the OIDC button, the username and password subscript, currently built using FACILITY + "account username", become misleading as they are used by functional accounts only.

Expected Behaviour

Add an option in the configs to determine what should be shown there

Here you should include details about the system (if it is unique) and possible information about a fix (feel free to link to code where relevant). Screenshots/GIFs are also fine here.