Add ECDSA check to L1 contracts

[just-mitch]

Probably the first go at SPRTN will be passing a list of signatures to our DA solution (i.e. eth calldata).

So we need to add that functionality, and expose it in our DA oracle.

Then we need to test, and show a benchmark of gas cost per signature included, up to 300 signatures.

[LHerskind]

This was addressed as part of #7579 in #7597