* add defaults for `getpeerinfo` and `getblocksubsidy`
* add default for `getmininginfo`
* add default to `getblockcount`
* add defaults to `getaddressbalance`, `getaddressutxos` and `getaddresstxids`
* add defaults to `validateaddress` and `z_validateaddress`
* add defaults to `getrawmempool` and `getdifficulty`
* add defaults to `sendrawtransaction` and `getrawtransaction`
* add defaults for `getnetworksolps` and `getnetworkhashps`
* add defaults for `submitblock` and `z_listunifiedreceivers`
* refactor and cleanup
* update spec
* add random request id
* add min transaction size to `GetRawTransaction` default
* improve `GetSubtrees` default
* change type to request id
* get new spec
* add a TODO
* add changelog entry