refactor: make tests agnostic to node

In #882 we converted some integration tests to unit tests that use the `MockRpcApi`. Ideally we would want most of the tests to use the mock but the client's test but node integration is also something we want to test.

Ideally we would have a set of tests that could be ran independently of the node used. This would need a bigger refactor on how we deal with tests, as the separation between integration and unit would disappear. One could run the tests with the mock for a fast check and with a real node for a thorough integration check.

This is also related to #872 and could probably be tackled together.

> I think something that would be cool might be to be able to run these tests (and any others) against the actual node instead of the mocked RPC API, but probably some more work will be needed. This way, we could have different sets of tests to run to validate the network's behavior.

_Originally posted by @igamigo in https://github.com/0xMiden/miden-client/pull/882#pullrequestreview-2858956534_