Allow super admins to switch roles

[jp524]

Resolves #4293.

Description

• [x] Can switch back and forth between superadmin and orgadmin properly as described
• [x] There is only one way to switch back and forth between superadmin and orgadmin
• [X] tests to support above

Type of change

• Bug fix (non-breaking change which fixes an issue) -> should resolve issues when trying to switch between roles using links "My Organization" and "Administration. Those are now removed since no longer needed
• New feature (non-breaking change which adds functionality) -> properly implement switching of roles for super admins

How Has This Been Tested?

Added some new system and request tests for this feature.

Screenshots

Switching between super admin and org admin

Super admin dashboard if user doesn't have other roles

[cielf]

Thank you! I brought this up and checked out the functionality -- looks good! I noticed some other issues around what happens if you have a super user with a role on an organization , but they are both pre-existing and out of scope for this change. Requesting a technical review from @dorner as the next step.

[dorner]

All good on my end! @cielf will give you the honors of final approval.

[cielf]

Still looks good!