Reduce time required to run permissions checks for the navigation.

Summary

Initialization of the navigation takes 20-25% of rendering time for the initial page load (this is consistent with the sidebar the new navigation replaced, there's no evidence of degradation).

See #395083 (comment 1461830484)

There may be an opportunity to tune this up.

Proposal

Reduce rendering time by:

• Aggregate Feature, License, Ability checks
• Cache the whole thing for the current user