Don't show firstname, lastname and email for any users

[maxceem]

In general: we should stop requesting and showing first name and last name of users client-side and show the handle instead everywhere.

• don’t request firstName and lastName in all endpoints client-side from the _search endpoint
• show handle instead of full name everywhere Client-side
• don’t request firstName and lastName in all endpoints server-side from the _search endpoint so we never return it to the client-side

[maxceem]

Hotfixes have been deployed to DEV:

• client-side: don’t request firstName and lastName in all endpoints client-side from the _search endpoint
• server-side: don't return firstName, lastName and email to non-admin users

@vikasrohit this is ready for testing on DEV.

PRs for PROD:

• clinet-side: [HOTFIX] [PROD] hide firstName, lastName and email #3805
• server-side: [HOTFIX] [PROD] Don't return fullname and email topcoder-platform/tc-project-service#510

[lakshmiathreya]

@drasticdpk