Feat/prsd 358 create controller and service

[JasminConterioSW]

This isn't quite there but I find that PRs are a useful place to ask questions!

In this PR:

• Add LA_ADMIN or LA_USER roles if a user logs in who is in the local_authority_users database
• Add a ManageLocalAuthorityUsersController which loads a placeholder page if the logged in user is an LA_ADMIN
• Get a list of Local Authority Users who are in the same local authority as the logged in user, show their userNames and access levels (isManager)
• Added tests for the controller to check that the page only checks shown to authorised LA_ADMIN users

To do - add some tests for the services:

• test the UserRolesService.getRolesForSubjectId function - are the landlord, la_user and la_admin roles getting added correctly?
• test the LocalAuthorityDataService.getLocalAuthorityUsersForLocalAuthority - this is doing some mapping so check it's being returned correctly
• test the getLocalAuthorityForUser service - this should return a Local Authority if the logged in user is in the local_authority_users database and should return null if they are not.

[JasminConterioSW]

I've now added some service tests, updated the landlord repository and updated the readme.
I haven't added the teamDL dummy accounts yet (mainly because I need to wait for it to log me out...) but can put that in the next PR

EDIT: Or I could use incognito mode to make it forget me...

EDIT AGAIN: I've added dummy accounts for a landlord, la admin and la user. The details are in keeper :)

[Travis-Softwire]

Subject to the point about looking up by entity rather than Id I'm happy with this :)