client: RPC get block transaction count by number

[am1r021]

Implements eth_getBlockTransactionCountByNumber rpc endpoint for #1114.

[codecov[bot]]

Codecov Report

Merging #2188 (c79a01e) into master (1a9da6f) will increase coverage by 0.06%. The diff coverage is 56.00%.

Additional details and impacted files

Flag	Coverage Δ
block	92.86% <ø> (-0.03%)	:arrow_down:
blockchain	90.21% <ø> (+1.73%)	:arrow_up:
client	86.91% <56.00%> (-0.04%)	:arrow_down:
common	98.37% <ø> (+0.28%)	:arrow_up:
devp2p	92.40% <ø> (-0.09%)	:arrow_down:
ethash	∅ <ø> (∅)
evm	79.23% <ø> (-0.02%)	:arrow_down:
rlp	∅ <ø> (∅)
statemanager	88.43% <ø> (-0.04%)	:arrow_down:
trie	90.36% <ø> (+0.93%)	:arrow_up:
tx	97.98% <ø> (ø)
util	88.99% <ø> (-3.34%)	:arrow_down:
vm	85.31% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[jochem-brouwer]

Could you add a test for this one? There's also a console.log left :)

[am1r021]

Yes, I'll take care of that. Picking this PR back up.

[acolytec3]

So I didn't realize we had left this one open but this was completed in #2379. Sorry we didn't see and merge this earlier! I'm going to close for now as it accomplishes the same thing.