L2: Improve tests

[fborello-lambda]

At the moment we use the ci_test/test make target from the Makefile located at crates/l2.

We may want to test some functionalities of the following modules/structures/abstractions:

• EthClient
• sdk
• calldata parser

We can take advantage of the setup the ci_test performs. For example, if we want to add a new test we can do the following, and then we can run the tests with:

cargo test l2 --release -- --nocapture --test-threads=1

--test-threads=1 is to avoid parallelization, if we use the same account we may have some troubles, we can use a different rich account for each test, in that way we shouldn't have problems.
cargo test l2 will match tests that has l2 in the function. [docs]

PR #1619 has the first test for an sdk's function (deploy())