Implement incremental, sparse note commitment trees for Sapling and Orchard

[dconnolly]

Implement the note commitment trees in order to compute anchors, for

• Sapling
• Orchard

In that order.

The follow-on to #286

Pertains to #983 , #958

Follow ups:

• Implement incremental, sparse note commitment trees for Sprout #2484 Implement the Sprout tree
• Add sapling and orchard anchors to zebra-state #1320 write Sapling and Orchard anchors and trees in the state
• Add sprout anchors to zebra-state #2485 write Sprout anchors and trees in the state
• Validate Orchard and Sapling anchors in non-finalized state #2530 validate the anchors

[teor2345]

@dconnolly hey did you want to split this work into separate tickets or PRs for sprout, sapling, and orchard?

[mpguerra]

Since the sprout parts have now moved to #2484 can we consider this issue done now that #2407 has merged?

[teor2345]

Since the sprout parts have now moved to #2484 can we consider this issue done now that #2407 has merged?

No, we still need to use these calculations in the state to finish #1287.
See #2407 (comment)

[conradoplg]

I've update the issue to restrict its scope to the trees themselves. We should be able to close this now.

[dconnolly]

Resolved by #2458