[Lens] Bail out of suggestion rendering if load times are too long

[flash1293]

Suggestions are expensive because every single one has the performance characteristics of a separate rendered chart (especially on Elasticsearch side in terms of generated queries).

If rendering is slow, we should stop rendering suggestions of fall back to simple icons instead.

We need to decide on a metric when to trigger this behavior and when to kick rendering back in - I suggest the following:

• If a suggestion takes longer than 30s (can be detected by waiting for onData callback), stop rendering suggestions
• Store this in a flag in the module state (will stick with the session - a refresh will bring back rendered suggestions)

Show a little warning icon next to the suggestion refresh button to make it obvious what's happening.

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[stratoula]

We don't rendert the charts in suggestions in recent kibana versions so this is not relevant anymore