Create updateUserAfterRegistration endpoint

[davidpmccormick]

Part of wellcomecollection/wellcomecollection.org#7808

Opted to create a new endpoint and handler instead of wrapping updateUser in conditionals based on whether we've got a password or not.

I think the user_id we're going to pass from the NextJS app will be prefixed with auth0| and I imagine we'll need to strip this off in order for the getTargetUserId function not to blow up. I've seen elsewhere we're checking if it starts with auth0|p – I'm not sure where that p comes from (and it doesn't appear in the ids that I've been testing with)

Edit: I've removed the auth0| (and maybe p) before it gets this far. I guess the p is for 'patron', although I wasn't sure if it would be added to newly created Sierra-database records using Auth0 as a way to signup, so left it optional for now. If we know the prefix either definitely will or will not contain a p, we can remove the ? or the p from the regex, respectively.

[jamieparkinson]

Can you add a comment about why this is a new endpoint? Reading the PR, I was initially against it as it's not very RESTful at all and it's definitely duplication, but I changed my mind because I thought (a) it seems reasonable that these endpoints will diverge (eg, we might want to send transactional emails here at some point in future) and (b) we can do a check that the user is at the correct stage of the signup process here.

[jamieparkinson]

Further thoughts:

• The ID will always include a p - this might be some useful context if you look at where it's used?
• You need to let the authorizer know about this endpoint here
• This will also need some terraform additions in API gateway for it to work (can do in a separate PR). It looks like a lot but it really is almost entirely copy-and-paste:
  1. For a new route you need an aws_api_gateway_resource, and then for each method (eg PUT) that might be used you need a aws_api_gateway_method, and for each response that a given method can have you need a aws_api_gateway_method_response. Example for OPTIONS /users/:id here.
  2. To connect the resource to the API you need an aws_api_gateway_integration for each method. Example for GET /users/:id here.
  3. You also need to add stuff for documentation, but in the course of writing this I think I've decided we should delete the documentation...

[davidpmccormick]

The ID will always include a p - this might be some useful context if you look at where it's used?

Does it make sense to send the whole prefixed id (e.g. auth0|p12345678) through to this app and remove the prefix here, or strip it before it gets here, just sending 12345678?

[jamieparkinson]

This endpoint needs to match the others in the API - the auth0|p prefix is private, and the routes should only include the plain 1234567. The authorizer won't work if it's any other way.

[davidpmccormick]

I think I've addressed the comments with the exception of the API gateway stuff (which I think I'd prefer to do and understand in a separate PR).