rpc: Added totalSigs to JSON response for scriptToJSON

[Nathanwoodburn]

• Added totalSigs property to the JSON response object
• Use getMultisig() function to return n value if available

[rithvikvibhu]

I'm still not sure about the name totalSigs because the script itself doesn't have any sigs, maybe maxSigs or something else?

Anyway, this works fine:

❯ hsd-cli rpc decodescript 52210264a3da1824775466f384369f90afb2f1d808336460595949c0d29c9148faf4dd2103101876dd6cfbf0500d2ac50e0462733180a5ec379dec6adea0e12c14cc053a28210369c50833277fb85ffc63e975a876a2ed6f5bd902749b4ba234b527f9e12c3e5253ae
{
  "asm": "OP_2 0264a3da1824775466f384369f90afb2f1d808336460595949c0d29c9148faf4dd 03101876dd6cfbf0500d2ac50e0462733180a5ec379dec6adea0e12c14cc053a28 0369c50833277fb85ffc63e975a876a2ed6f5bd902749b4ba234b527f9e12c3e52 OP_3 OP_CHECKMULTISIG",
  "type": "MULTISIG",
  "reqSigs": 2,
  "totalSigs": 3,
  "p2sh": "hs1q0kx4hladgefst0vk005e8ez7xejvw2jw7gaftny3a5savp5k3jwswsgrc6"
}

[Nathanwoodburn]

We could change it to m and n except that would break existing applications using the RPC