[WPB-10314] validate swagger: fix more errors

[fisx]

disambiguate paths:

PUT /users/:uid/email => PUT /users/uid/:uid/email GET /users/:uid/rich-profile => GET /users/uid/:uid/rich-profile [TODO: ...]

(without these, which route is selected depends on the order in which they are matched, eg. /users/handle could be stolen by /users/{uid}.)

Checklist

• [ ] Add a new entry in an appropriate subdirectory of changelog.d
• [ ] Read and follow the PR guidelines