Tx: Finalize AccessList API

[holgerd77]

The API for the Transaction library for EIP-2930 access list access was a bit side introduced and didn't get a proper review on merging #1148.

I think we should give this some additional reflection before exposing (currently this is excluded from the doc generation), some open questions:

• Is this the best way to expose this functionality or might there be better - eventually more integrated - solutions (e.g. to re-bind the methods to the affected tx classes, just as some first idea)?
• Relationship of this getAccessListData() (returning AccessListJSON as one of two items) and the getAccessListJSON() method
• Should getDataFeeEIP2930() be exposed (I have the base feeling that methods which need a Common as an input often point to some suboptimality in design - we had these cases in the past - can't really point towards a concrete solution thought atm yet)?

The names of the methods should also get some additional look.

[holgerd77]

Still relevant and needs to be tackled before we can properly expose the functionality.