add(tests): Add snapshot tests for sprout database formats

[teor2345]

Motivation

We're changing our database note commitment tree format code in PR #7053, but we don't have good coverage for sprout trees. (We have snapshots for the raw data, but not converting it into Zebra's data structures.)

Reference

RocksDB Iterator Mode:
https://docs.rs/rocksdb/latest/rocksdb/enum.IteratorMode.html

Snapshot redactions:
https://insta.rs/docs/redactions/#sorted-redactions

Complex Code or Requirements

Using database iterators like this has caused hangs before, but so far these methods are only used in tests.

Solution

Empty Note Commitment Tree snapshot tests:

• Add snapshot tests for sprout note commitment trees
  • Add a method that loads all the sprout trees from the database
  • Add methods for loading entire column families from the database

Sprout Note Commitment Tree manual snapshot tests:

• Add a manual sprout note commitment tree database serialization snapshot test
• Add tests for 1,2,4,8 note commitments in a tree
• Randomly cache roots rather than only caching even roots

Tree Root tests:

• Add round-trip proptests for tree root database serialization

Related Fixes:

• Remove redundant "rand" package rename in dependencies

Review

@oxarbitrage might find this handy for testing PR #7053.

Reviewer Checklist

• Are the PR labels correct?
• Does the code do what the ticket and PR says?
  • Does it change concurrent code, unsafe code, or consensus rules?
• How do you know it works? Does it have tests?

Follow Up Work

We still don't have some snapshot tests for the entire database, or for some shielded data. (We only use 10 blocks, but the first Sprout transaction is after 100+ blocks.)

We can add them as we change the database format.

[codecov]

Codecov Report

Merging #7057 (ea8f5fd) into main (a6f35af) will decrease coverage by 0.07%.
The diff coverage is 82.19%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7057      +/-   ##
==========================================
- Coverage   77.52%   77.46%   -0.07%     
==========================================
  Files         310      310              
  Lines       41694    41767      +73     
==========================================
+ Hits        32325    32353      +28     
- Misses       9369     9414      +45     

[oxarbitrage]

Failed by container issue. Restarting all jobs

[teor2345]

Failed by container issue. Restarting all jobs

It first failed at the create instance stage:

ERROR: (gcloud.compute.instances.create-with-container) Could not fetch resource:

<title>Error 502 (Server Error)!!1</title>

502. That’s an error.

The server encountered a temporary error and could not complete your request.

Please try again in 30 seconds. That’s all we know.

https://github.com/ZcashFoundation/zebra/actions/runs/5353701092/jobs/9711197294?pr=7057#step:11:91

[teor2345]

@Mergifyio update

[mergify]

update

✅ Branch has been successfully updated

[oxarbitrage]

This looks and works very good, it will be needed to test the ECC dependency upgrades of #7053