Add phone number as editable to users

[mveytsman]

Describe your changes

The phone number for user field wasn't editable (to be fair it should be the same number as the associated rider but this is an improvement at least)

Checklist before requesting a review

• I have performed a self-review of my code
• If it is a core feature, I have added tests.
• Are there other PRs or Issues that I should link to here?
• Will this be part of a product update? If yes, please write one phrase
  about this update in the description above.