[P2] Implements RIP-7728

[mralj]

Actual L1SLOAD precompile implementation

I think the PR is self-explanatory, I'm most interested in the feedback on the code style.
I like long descriptive names because, IMO, it makes reading code so much easier, but that's not in the Go's spirit here is a concrete example:

countOfStorageKeysToRead:= (len(input) - common.AddressLength) / common.HashLength
thereIsAtLeast1StorageKeyToRead := countOfStorageKeysToRead > 0
allStorageKeysAreExactly32Bytes := countOfStorageKeysToRead*common.HashLength == len(input)-common.AddressLength

if inputIsInvalid := !(thereIsAtLeast1StorageKeyToRead && allStorageKeysAreExactly32Bytes); inputIsInvalid {
    return nil, errors.New("L1SLOAD input is malformed")
}

As you can see, this is much more verbose than what we have in the geth code and what the Go styling guide suggests.
Still, I don't see downsides to writing code like this, only upsides - it will be much easier to review, understand and onboard.