[BACKEND] Update MembershipTypeValues to correct ones

[bcho892]

Is your feature request related to a problem? Please describe. Currently the types we have do not correctly reflect what it should be. Refactor all code that uses the wrong values if need be.

You will have to run yarn dev-server to regenerate both client and server types.

BEFORE MERGING

• [ ] Integration test written for services
• [ ] Schemas annotated if adding new models
• [ ] Code generation run (hint: yarn workspace server tsoa spec-and-routes)
• [ ] Appropriate mocks created where possible
• [ ] PR Reviewed (For non-trivial changes)
• [ ] Changes tested after rebasing on master or merging in master (hint: git fetch origin master:master, then git rebase master or git merge master)
• [ ] All required PR checks passing