Add keystone performance chart and trigger, when maximal limit reached

Please add keystone performance chart and trigger, when maximal limit reached.

We should have one or two charts, related to keystone performance:
1. Token requests/Tokens generated at the same chart
2. Token validation requests/Token validated

Y axis should contain numbers of requests
X axis should contain timeline

At the same time we should have near all chart some decimal data places into table

------------------------------------------
| | |
|token requested | ХХХХ |
|----------------------------| |
| tokens provided | YYYY |
|----------------------------------------|

and

----------------------------------------------------------
| | |
|token validation requested | ХХХХ |
|-------------------------------------------|-------------|--------------------|
| tokens validated | YYYY | |
|-------------------------------------------|-------------|YYYY+ZZZZ |
| tokens expired ZZZZ | |
-------------------------------------------------------------------------------

something like YYYY+ZZZZ ~= XXXX

If maximal limit is reached for token requests or token validation request grafana should show warning.

maximal limit should be provided by keystone developers

Also to create more detailed warnings into grafana we can split "OPENSTACK SERVICES" buttons on main page and put there warnings.

All "buttons" can be splitted to the lines, and eacj line can change color related to problem (green/yellow/red)

------------------------------------
| Keystone |
| |
| Token GET: WARNING |
| Token validation: OK |
| |
| Keystone services: |
| total 3 nodes |
| up 3 nodes |
| down 0 nodes |
| |
| |
| |
| |
|-----------------------------------|

------------------------------------
| Keystone |
| |
| Token GET: WARNING |
| Token validation: OK |
| |
| Keystone services: |
| total 3 nodes |
| up 2 nodes |
| down 1 nodes- |
} node-XXX |
| |
| |
| |
| |
|-----------------------------------|