Refactor getUserByFirebaseId subscriptions

[eleanorreem]

Overview

We want to start breaking up the GET /user/me request and only fetch information on the pages it is needed. This is starting with subscriptions. We created a new endpoint in this ticket to have a bespoke endpoint for getting subscriptions . The frontend migration is in this ticket and blocks this refactor. After the frontend has been migrated over, we can start breaking up the GetUserDto and remove subscriptions from the object.

Action Items

• Remove leftJoins of subscription and subscription_user table from the database query in userService.getUserByFirebaseId.
• This will impact the firebase module and therefore the rest of the site. There may be significant refactors ahead.
• You will need to remove subscription_user and subscription imports from most modules as they will no longer be required.
• Remove all instances of ISubscriptionUser. It should either be an entity or a dto.
• Remove subscriptions property from the GetUserDto.