endpoint to update user

[jocrah]

Task Description

We need an endpoint to update a user's information. This is to allow a user to update user information including other fields which are not taken when creating a user. These include jobRole, department etc.

Technical Considerations

1. Take note of the optional fields in the users table that are not taken when a user is being created. (The role column is an intentional exception because we do not allow users to set their own roles due to security implications.)
2. Create a PATCH users/:id endpoint with the fields noted in step 1 as optional fields

Additional Considerations

Add related tests and add corresponding documentation