fix(test): make the full sync tests cache state at /zebrad-cache

[teor2345]

Motivation

This PR completes ticket #3545, by caching the state at the location required by the disk image workflow.

We mistakenly skipped part of this step in the ticket:

Create a test similar to sync_to_mandatory_checkpoint_* that syncs to a blockheight (NU5 activation?) and stops This exists as the full sync test to tip.

The test existed, but it cached its state in an ephemeral directory, rather than at a fixed path.

Solution

• Use the same code and state path as the mandatory checkpoint state and full validation sync test
• Move the tests so they are near the mandatory checkpoint tests

Review

@dconnolly can review this urgent PR, it blocks most of the lightwalletd test work.

Reviewer Checklist

• Code implements Specs and Designs
• Tests for Expected Behaviour
• Tests for Errors

[teor2345]

@gustavovalverde I'm running a full sync at:
https://github.com/ZcashFoundation/zebra/actions/runs/2274405176

I tested it using:

RUST_BACKTRACE=full FULL_SYNC_MAINNET_TIMEOUT_MINUTES=1 cargo test --locked --release --features enable-sentry --test acceptance -- --nocapture --ignored full_sync_mainnet

and it uses the /zebrad-cache path on my machine.

That seems to be the default path for the full sync test in CI, so we should be good here.

[gustavovalverde]

I just confirmed the container is writing to the disk