[INTW26] Implement reviewer authorization

[gavxue]

Notion ticket link

Implement reviewer authorization

Implementation description

• created isAuthorizedReviewer interface and implementation
• also add appropriate types and graphql resolver

Steps to test

1. sign in with Google OAuth on the frontend (localhost:3000/admin)
2. use inspect tool and go to the Application tab
3. under local storage, copy the corresponding value of the key accessToken
4. test the following graphql query

query {
  isAuthorizedReviewer(
    accessToken: <YOUR_ACCESS_TOKEN>,
    applicantRecordId: <APPLICANT_RECORD_ID>
  )
}

Use the access token you copied previously. You can get applicant record ids by going to the reviewed_applicant_records table in the database. You can also check your id in the users table
5. test that the query returns true if you have a valid accessToken, valid applicantRecordId, and are actually assigned to review that applicant
6. test that the query returns false for any other scenario

What should reviewers focus on?

• checking if implementation of the function makes sense

Checklist

• My PR name is descriptive and in imperative tense
• My commit messages are descriptive and in imperative tense. My commits are atomic and trivial commits are squashed or fixup'd into non-trivial commits
• I have run the appropriate linter(s)
• I have requested a review from the PL, as well as other devs who have background knowledge on this PR or who will be building on top of this PR

[mxc-maggiechen]

LGTM! Works great 😄

[SaqAsh]

Couldn't find anything to nit :) LGTM

[chene0]

LGTM