feat(coderd): set full name from IDP name claim (#13468)

* Updates OIDC and GitHub OAuth login to fetch set name from relevant claim fields
* Adds CODER_OIDC_NAME_FIELD as configurable source of user name claim
* Adds httpapi function to normalize a username such that it will pass validation
* Adds firstName / lastName fields to dev OIDC setup

coderd/apidoc/docs.go

@@ -10551,6 +10551,9 @@ const docTemplate = `{
                 "issuer_url": {
                     "type": "string"
                 },
+                "name_field": {
+                    "type": "string"
+                },
                 "scopes": {
                     "type": "array",
                     "items": {