709998467e rpc: doc: Fix and extend getblockstats examples (Adam Soltys)
Pull request description:
This pull fixes the example curl command for `getblockstats` which doesn't work as is because it's missing a comma between the params and has single quotes around the second parameter.
It also adds an additional example of getting block stats by hash by using a known workaround (#15412) to get bitcoin-cli to treat the hash parameter as JSON instead of a string since there is ongoing deliberation about how or whether to fix the root issue (#15448).
ACKs for top commit:
theStack:
ACK 709998467e
Tree-SHA512: 84a5b7f449f06fff785bc0afbc1a7dfd55454bc76c52a8945e91556f87f3edfdc5a1780faab8fcfd6c415b734295b7c67d2e04ba7b6cfa91a77758af5dda53ae
5e5dd9918e