feat[contracts]: Restrict tx nonce and gasLimit to uint64

[smartcontracts]

Description
Restricts nonce and gasLimit transaction fields to uint64. Also restricts the nonce field within the account struct to uint64.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 135a0aa

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[transmissions11]

Does gasPrice have to be uint256 or could it also become uint64 (it could fit a gas price up to 50 ETH)

[maurelian]

Is the motivation here to save gas? Have we measured the difference?
I imagine this will save gas on calldata (space), but cost more for computation during fraud proving (ex).

Edit: Oh, I see it's about compatibility with geth.

[maurelian]

LGTM once integration tests are passing.

[smartcontracts]

Closing this for now until we can confirm that we actually care about this restriction