Added separate endpoints to handle eggs (get, update and delete)

[GamrayW]

As discussed on discord, creating the endpoints on the backend to separate save request.

Only the enpoints for the eggs on this PR is implemented: GET /savedata/eggs to retrieve list of the eggs an account has POST /savedata/eggs to update the eggs values POST /savedata/deleteeggs to delete eggs

With those endpoints and the handlers, there's a new table "eggs"

Here's the tests I made, you can replicate by changing the token to an account on your instance:

[slsyy]

@UpcraftLP could you review it?