The 'name' field was really redundant and caused confusion in the
codebase, since the 'Display' name is often used and we have a
'system_name' for the admin and public role.
This fixes#2032, Where external auth group matching has confusing
behaviour as matching was done against the display_name, if no
external_auth field is set, but only roles with a match 'name' field
would be considered.
This also fixes and error where the role users migration, on role
delete, would not actually fire due to mis-matching http body keys.
Looks like this has been an issue from the start. Added some testing to
cover. Fixes#2211.
Also converted phpdoc to typehints in many areas of the reviewed code
during the above.
