[new UD] Improve Keycloak token refreshing

[akurinnoy]

Is your task related to a problem? Please describe.

After introducing the che-workspace-client in order to perform REST API request in new dashboard (PR) it lost the ability to refresh the Keycloak token.

Describe the solution you'd like

The che-workspace-client should be able to expose an Axios instance. So, we can register interceptor that refreshes keycloak token. Additionally, we'll be able to refresh token depending on user activity in UD even if no API requests are done.

Describe alternatives you've considered

As an alternative solution, provide to che-workspace-client ability to add/remove user defined interceptors. That allows us to refresh keycloak token only on API request.

[sleshchenko]

che-incubator/che-dashboard-next#86 partially or almost fixes issue with refreshing a token on the Dashboard Next.
But there still may be some corner cases that need additional fixes, as I faced with using expired token for establishing WebSocket connection, while I'm starting a workspace in tab that was inactive for some period (~5-10 minutes):

[sleshchenko]

Another case, create Custom Workspace when token is expired and I twice clicked Create and Open, first returns error, the second creates workspace without any issue:

is fixed by che-incubator/che-dashboard-next#110

[sleshchenko]

Closing the issue since the problems with requests with outdated tokens are fixed.
The websocket issue should be solved in the scope of #18490.

A dedicated issue is created to move interceptors on the workspace-client-lib side #18803