[RN] Add "Git Services" tab to the User Preferences

Synced from eclipse/che issue

https://github.com/eclipse/che/issues/21595

Is your task related to a problem? Please describe

Currently, the account page is outdated and fetches the user information from db that is planned to be removed as part of https://github.com/eclipse/che/issues/21374

The data provided on the Account page is irrelevant and should be removed

Describe the solution you'd like

As part of this issue, we should only have the login / logout buttons to the main Git providers GitHub, Gitlab, and Bitbucketlogin/logout

Sub-tasks

• [ ] remove dependecy on /user and /profile API (display only username from k8s as the first step)
  • [ ] hide 'Account' view
• [ ]

Describe alternatives you've considered

Potentially we should remove Account page completely and add Git Services Tab to the User Preferences:

Additional context

The information about the configuration of the particular Git provider should be fetched from the Eclipse Che CR - https://github.com/eclipse/che/issues/21577

The issue is part of the Git Zero Config epic - https://github.com/eclipse/che/issues/20583

Open Questions:

• login / logout URLs should be provided by the Che CR
• how should we track the login / logout state for a particular user