accounts/abi/bind/v2: modify the default contract deployer to block until the tx is accepted/rejected from the pool

[jwasinger]

This aims to fix some flaky tests in this package, and also fixes a valid issue that could affect users.

If the deploy invocation is part of a set of deployments and the nonce is nil in the TransactOpts, the tx nonce will be automatically determined by looking at the pending nonce in the txpool.

If there are subsequent dependent deployment transactions, we want to make sure that prior transactions had a chance to be accepted into the pool so that the nonces on all the transactions are set correctly.

TODO: Also, in the case of a multi-contract deployment where TransactOpts has non-nil nonce, we should not determine the txs' nonces based on the pending from the pool. Instead, we should start incrementing from whatever was provided in the TransactOpts.

[jwasinger]

It's IMO a bit unfortunate that this method is on the ContractTransactor and not the DeployBackend interface.

However, the method signature of DefaultDeployer takes a ContractBackend. In order to not break compatibility, and make sure that this fix can apply to the default deployer, I decided to put TransactionsByHash here.

[jwasinger]

hmmm. still seeing failures:

1m5s: 6558 runs so far, 0 failures, 12 active

/var/folders/fz/k1s_1m8n0md3v58rxwzdsb2h0000gn/T/go-stress-20250708T204733-1186997902
--- FAIL: TestDeploymentLibraries (0.02s)
    lib_test.go:85: err: replacement transaction underpriced

Perhaps the fix here isn't sufficient to address the flaky tests.