* Fix eth/common & web3 related deprecation warnings for fluffy
This commit uses the new types in the new eth/common/ structure
to remove deprecation warnings.
It is however more than just a mass replace as also all places
where eth/common or eth/common/eth_types or eth/common/eth_types_rlp
got imported have been revised and adjusted to a better per submodule
based import.
There are still a bunch of toMDigest deprecation warnings but that
convertor is not needed for fluffy code anymore so in theory it
should not be used (bug?). It seems to still get imported via export
leaks ffrom imported nimbus code I think.
* Address review comments
* Remove two more unused eth/common imports
* Support RPC API namespaces as cli parameter.
* Fluffy now uses rpcFlags on startup.
* Update testnet script to enable all RPC APIs.
* Update Fluffy book and move web3 call into eth calls.