[#13173] Fix SearchAccountRequestsActionTest

[jasonqiu212]

Fixes #13173

Credits to @domoberzin for helping me debug this!

Problem

• SearchAccountRequestsActionTest inserts Datastore-version of account request documents into Solr via putDocuments(dataBundle)
• SearchAccountRequestsAction searches using sqlLogic.searchAccountRequestsInWholeSystem, which leads to sqlsearch.AccountRequestSearchManager::getEntityFromDocument getting called. But since Solr only contains Datastore-version account request documents (which do not have UUID as ID), it will lead to an IllegalArgumentException when trying to parse the ID into a UUID.

Solution

• Revert sqlsearch.AccountRequestSearchManager::getEntityFromDocument to get account request using email and institute, instead of ID, since email and institute already uniquely identifies an account request

Testing

Run the following command:

./gradlew unitTests --tests SearchAccountRequestsActionTest

Notes

• Still not really sure why this test fails when running individually, but passes when running together with the other unit tests
• There are 2 versions of AccountRequestSearchManager: 1 for Datastore and 1 for SQL. Both versions are called to find account requests from Solr in SearchAccountRequestsAction. But only Datastore-version account request documents are inserted. Do we need to insert in the SQL-version account request documents as well? If yes, XXXSearchManager needs a way to differentiate between Datastore-version documents and SQL-version documents. But we will probably not fix this, since this test will likely be phased out after the migration is complete. A new migrated test will need to insert in SQL-version documents.
• Why didn't the other SearchInstructorActionTest and SearchStudentActionTest fail? Because the SQL-version of InstructorSearchManager and StudentSearchManager search using email and institute, which is the same as their Datastore counterparts.

[jasonqiu212]

Now it's failing E2E tests..