Make different presentation for unavailable metrics

The problem: 

When users trying to change Metric it's usually a lot of values and users need to know e lot about metrics. it's sometimes easy to select metric you  don't  have in the current selection 

User Story: 

As PMM user, I  need to see metrics which are not present in the current data set, so that i can easily see what's available for selection  

Proposed solution

1) have Metrics in the list sorted by "availability" and next by  A-Z  

2) Use different  "color"  (UX needed ) for presenting Available and unavailable metrics 

Suggested implementation:

 -  Extend API with an endpoint that returns a list all metrics with an indication which is available for given time range and selected filters.

 - Implement in qan-api2 method to select available metrics:

[UI part] UI can cancel the query if it runs longer then 3 sec and shows metrics that they already have with a note:

get only available metrics takes too long - show all queries

Or 

1) Selected metrics taking too long - showing all
2) Slow response from selected metrics - showing all
3) Your selected metrics are slow to respond - showing all instead