update to iavl 0.11.0

[ValarDragon]

This has a measurable state machine performance improvement (2% at minimum according to simulation). I think we should try to get this into the next SDK release.

• Targeted PR against correct branch (see CONTRIBUTING.md)

• Added entries in PENDING.md with issue #

• rereviewed Files changed in the github PR explorer

---

For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #2281 into develop will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff            @@
##           develop    #2281   +/-   ##
========================================
  Coverage    63.83%   63.83%           
========================================
  Files          140      140           
  Lines         8666     8666           
========================================
  Hits          5532     5532           
  Misses        2754     2754           
  Partials       380      380

[liamsi]

LGTM!

[cwgoes]

utACK