feat: indexed protocol contracts tree

[MirandaWood]

Closes #11843

This PR converts the protocol contract address tree to an indexed tree. This is so:

• If a user is calling a protocol contract address, its calculated address must be in the tree
• If a user is NOT calling a protocol contract address, its calculated address must NOT be in the tree

This required more changes than expected because the old code had this statement:

    let computed_protocol_contract_tree_root = if (MAX_PROTOCOL_CONTRACTS as Field).lt(
        protocol_contract_index,
    ) {
        0
    } else {
        root_from_sibling_path(
            computed_address.to_field(),
            protocol_contract_index,
            private_call_data.protocol_contract_sibling_path,
        )
    };
    assert(
        computed_address.eq(contract_address)
            | computed_protocol_contract_tree_root.eq(protocol_contract_tree_root),
        "computed contract address does not match expected one",
    );

For many tests in and out of nr, we input protocol_contract_tree_root = 0. That meant that even if we weren't calling a protocol contract address, an incorrect contract_address would pass the assert statement. The current code does not allow this, so I had to update some old fixtures and provide a real root for all calls (not just protocol contract ones).

[MirandaWood]

Note that I didn't change anything that caused these fixtures to update - they hadn't been updated in a while because the final address value was never tested, so passed when it should have failed.
This is because the tests set protocol_contract_tree_root to be 0, so the contract address checks would pass even if there was a computed address mismatch (see old code in validate_contract_address for the if statement).

[MirandaWood]

I edited this because there was a mismatch in the noir fixtures - the nr versioned hashed the vk, while the ts did not. This never became an issue because of the above comment.

[github-actions]

Changes to circuit sizes

Generated at commit: c264b3e1dcdd1f0a8114e60158d03845e38c5486, compared to commit: 7901cacd898f9df806942cbe8e454aef2fd8e5c3

🧾 Summary (100% most significant diffs)

Program	ACIR opcodes (+/-)	%	Circuit size (+/-)	%
private_kernel_init	+179 ❌	+0.96%	+446 ❌	+1.12%
private_kernel_inner	+179 ❌	+0.63%	+446 ❌	+0.62%

---

Full diff report 👇

Program	ACIR opcodes (+/-)	%	Circuit size (+/-)	%
private_kernel_init	18,858 (+179)	+0.96%	40,292 (+446)	+1.12%
private_kernel_inner	28,546 (+179)	+0.63%	72,679 (+446)	+0.62%

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