Change "User ID" Label to "Username" in Users

Purpose: We want to line up the UI elements with the API names. The SIG had originally defined "User ID" as the name for the login ID but on the back end it was implemented as "username". Because changing the backend is difficult, the SIG has agreed to change the front-end label.

Acceptance Criteria:

• Change "User ID" to "Username" wherever it displays in Users:
  • User details view mode (preview pane)
  • User details edit mode
  • User details create mode
  • User app search results
  • Anywhere else you can find?