Remove org admin switch when creating user

[vinayvenu]

Acceptance criteria

• The "Make this user an administrator ..." switch is removed from the Users screen
• The "Role" column is removed from the User listing screen
• API will still accept the role flag, but valid values will be only user and admin
• Migrate all org-admin values in the database to "user" (need to check if this is possible)

We will eventually replace this with the groups that a user has access to.

[petmongrels]

removing most preauthorise from server. removed admin and org_admin completely as role. only one role left 'user'.

1. 'user' role disallows admin to make transaction data view and save
2. for 'admin' only endpoints putting a check for isAdmin via accessControlService

[petmongrels]

• instead of creating new privilege for these, using org config privilege - news, msg91config, task type, rule edit, metadata image.
• for privacy reasons applied edituserconfig privilege for viewing other users.
• adding Report (entity type = subject) and EditVideo privilege type. used entity type subject instead of creating one more entity type. we will have to change it based on how we want to show it on the UI