Add extra stats to getblock

[aguycalled]

This pull request adds a few extra fields in the output of getblock

• tx_count count of transactions of the block
• proposal_count count of proposals created in the block
• payment_request_count count of payment requests created in the block
• proposal_votes_count count of votes for proposals in the block
• payment_request_votes_count count of votes for payment requests in the block
• payment_request_payouts_count count of payouts from payment requests in the block

What to test

• The new fields of getblock <blockhash> must show the right values.

[navbuilder]

A new build of 74fb1c5 has completed succesfully!
Binaries available at https://build.nav.community/binaries/aguycalled-patch-4

[chasingkirkjufell]

tested gitian build on window 10 64 bit and worked as expected

scenarios:

created txs & proposals, voted on proposals, cancels votes, created payment requests, got payouts.

all counts were correct