Ensured new users do not get avatars missing resources

[barankyle]

Added logic to createNewUser to check that the avatar randomly selected for a new user has a valid model and thumbnail resource, and remove that avatar from the list to choose from if either is missing.

Summary

References

closes #insert number here

QA Steps

[barankyle]

@hanzlamateen I was initially just going to read the existence (or not) of the resources off of the avatars object returned from avatarPath.find, but they weren't there. I finally realized that was because the modelResource and thumbnailResource resolvers are on avatarExternalResolver, and this is an internal call. I wasn't sure we wanted to move them to avatarResolver just for this situation; do you know of a way to force a specific resolver to trigger by adding things to the request alone?

Since these resolvers are for external requests, I'd tried adding provider to the params to make it look like an external request, but that ran into a different issue, namely that there was no authentication headers since the user doesn't exist yet. Manually GETting the resources like I did doesn't seem like the most elegant solution, but I'm not sure if there's a better way to do it.

[hanzlamateen]

@hanzlamateen I was initially just going to read the existence (or not) of the resources off of the avatars object returned from avatarPath.find, but they weren't there. I finally realized that was because the modelResource and thumbnailResource resolvers are on avatarExternalResolver, and this is an internal call. I wasn't sure we wanted to move them to avatarResolver just for this situation; do you know of a way to force a specific resolver to trigger by adding things to the request alone?

Since these resolvers are for external requests, I'd tried adding provider to the params to make it look like an external request, but that ran into a different issue, namely that there was no authentication headers since the user doesn't exist yet. Manually GETting the resources like I did doesn't seem like the most elegant solution, but I'm not sure if there's a better way to do it.

@barankyle avatarResolver will be executed even for internal calls. So as in your case these resources can be move to avatarResolver.