feat(load): add trie stress test

[RodrigoVillar]

Why this should be merged

As mentioned in #3914 (comment), this is another test that we eventually planned on adding to the load package.

How this works

Adds a new TrieStressTest type along with its dependencies (contract code). This contract is from the following: ava-labs/subnet-evm#981

How this was tested

CI + ran load test locally

Need to be documented in RELEASES.md?

No

[Copilot]

Pull Request Overview

This PR adds a new trie stress test to the load testing package, designed to stress test Ethereum Virtual Machine (EVM) state trie operations by writing multiple values to contract storage.

• Adds a new TrieStressTest contract and corresponding Go bindings
• Integrates the trie stress test into the existing random weighted test framework
• Refactors existing code to deploy and use two separate contracts (simulator and trie stress test)

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
tests/load/tests.go	Deploys new trie stress test contract and adds it to the weighted test suite
tests/load/contracts/TrieStressTest.sol	Simple Solidity contract that writes values to storage array for trie stress testing
tests/load/contracts/TrieStressTest.bindings.go	Generated Go bindings for the trie stress test contract

Comments suppressed due to low confidence (1)

tests/load/tests.go:150

• The new TrieStressTest is missing a Weight field, which means it will have a zero weight in the weighted test selection. This could prevent the test from being executed in the random weighted test framework.

		{