Clean up and improve coverage

[holgerd77]

Will go a bit through the current master coverage build to roughly identify uncovered code parts to get a bit more of the total picture.

Goals are a bit in both directions:

• to identify where coverage is still low and how this can be improved, but also
• to identify unused or unoptimized code parts, (non-)coverage is also often an indicator here that code parts are not that much in production or even unnecessary

Some first things:

1. We were still running blockchain and coverage test runs towards Byzantium leaving the new opcodes oncovered (or reported to be covered at least), this PR is addressing this: Complete switch to Petersburg on tests | Fix coverage #448
2. Since we are not running Constantinople (the old one) fork rules for coverage the whole new SSTORE test is now left completely untested, we actually do might want to reintegrate some of just removed constantinopleSstoreTest test cases (see Test cleanup #437) to get some basic coverage, but maybe just as some single test cases in the new runCode API tests in some adopted format. Eventually these tests need also some modified setup to be a bit more flexible on adding new test cases, nevertheless a superb start that we have that at all
3. The vm/logTable.js file significantly adds to non-coverage. This is actually some static value setup for the EXP opcode. At the moment I see no reason why it shouldn't be possible to just inline a dynamic 1-2 line version of this into the EXP opcode and get rid of the file. I did a short test because I thought if there might be some performance reason for the code, but even running this for (let i=0; i<1000000; i++) { pow32 = new BN('010000000000000000000000000000000000000000000000000000000000000000', 16) } doesn't take a significant amount of time, addressed in Replaced static vm logTable with dynamic inline version in EXP opcode #450
4. fakeBlockchain is also contributing to non-coverage, getting rid of this is discussed here: Incorrect behavior of fakeBlockChain.prototype.getBlock #446
5. Same with createHookedVM, deprecation is in discussion here: Deprecate createHookedVm #435, addressed in Drop createHookedVm #451

List is likely not complete, if you have additions feel free to directly edit the post, eventually with closing with your GitHub name on the list item.

[holgerd77]

StateManager.dumpStorage() completely untested: https://coveralls.io/builds/21805704/source?filename=lib/state/stateManager.js#L432

[holgerd77]

Eventually for 2. some of the structure of the old hookedVM tests can be taken for inspiration.

[holgerd77]

1. Fixed by Complete switch to Petersburg on tests | Fix coverage #448
2. Taken over to SSTORE Test Coverage #502
3. Fixed by Replaced static vm logTable with dynamic inline version in EXP opcode #450
4. Fixed by Remove fakeBlockchain class and associated tests #466
5. Fixed by Drop createHookedVm #451

Will close.