Updated RPC methods to work with chopsticks

[x] Added state_getRuntimeVersion support
[x] Use chain_getBlockHash when chain_getHead is unavailable
[x] Use state_getStorage when state_getStorageAt is unavailable
[x] Case insensitive check for Finalized and InBlock extrinsic update messages
[x] Added backwards compatibility with older RPC
[x] Support for partial already decoded block header in newer Substrate RPC
[x] Updated unit tests
[x] Add additional unit tests where legacy RPC methods are not available
[x] Fix broken Include block author option

polkascan / py-substrate-interface