Create a state containing valid Sapling and Orchard blocks

[upbqdn]

In #8533, we needed a state which contains:

1. Blocks containing Sapling note commitments.
2. Blocks for which we could activate NU5, see Create a state containing post-NU5 blocks #8534.
3. Blocks containing Orchard note commitments.

There's currently no way to create such a state in Zebra. Having it is beneficial for tests, as mentioned below

zebra/zebra-rpc/src/methods/tests/snapshot.rs

Lines 54 to 63 in 824e520

	/// TODO:
	/// 1. Check a non-empty Sapling treestate.
	/// 2. Check an empty Orchard treestate at NU5 activation height.
	/// 3. Check a non-empty Orchard treestate.
	///
	/// To implement the todos above, we need to:
	///
	/// 1. Have a block containing Sapling note commitmnets in the state.
	/// 2. Activate NU5 at a height for which we have a block in the state.
	/// 3. Have a block containing Orchard note commitments in the state.

Depends on #8534.

[mpguerra]

@ZcashFoundation/zebra-team Is this still relevant?

[upbqdn]

Yes, it is. We currently don't have such a state in the tests.