util: Add SetupHelpOptions()
Every binary we have sets up the help option in their own way and wording.
Solve that by having one function take care of it for all of them.
Backport of Bitcoin Core PR#15358
Test plan: the following commands should print help, check help text of -?/-??.
bitcoind -?bitcoind -hbitcoind -helpbitcoind -??bitcoind -help-debugbitcoin-cli -?bitcoin-tx -?