General: Update any outstanding schema changes, create frontend 'client' objects

[izzyconner]

To create a layer of separation between our model data in our database and the 'client' data that the frontend expects, we should create separate versions of data objects that represent exactly what the frontend expects the data to look like (based off the existing model schemas like TimesheetSchema, etc. Eventually, this should just be one shared folder of types and classes when we move into the monorepo, but for now, we'll need to have these in the backend.

In addition to this, we've also made some recent updates to various data schemas, which need to be updated in the backend model and/or client objects: https://lucid.app/lucidchart/912e6933-6883-4402-b926-805c934ded0c/edit?viewport_loc=-1808%2C-316%2C5688%2C2992%2C0_0&invitationId=inv_4b8281c9-b632-4438-9daa-06e3716331c5

Conditions of Satisfaction:

• All data that is being returned in the AuthController and UserController should be a 'client' object that matches up with what the frontend is expecting. There should be a way to map data from the existing model schemas to the new client objects. A helpful funtion to reference is zod pick() and transform : https://c4cneuteams.slack.com/archives/C043TJM55BN/p1683765863039309?thread_ts=1683765847.042989&cid=C043TJM55BN
• All model data objects and sample data in DynamoDB should match the current data schema diagram linked above