* Remove getSszDecoded from ContentDb.
* Update ContentDb get to use onData callback to reduce copies.
* Use templates for helper procs in ContentDb.
* Add contains handler to portal protocol.
* Improve performance of DbGetHandler.
* Enable content cache for state network.
* Update state json-rpc endpoints to return local content which uses cache if enabled.
* Add content cache metrics.
* Make content cache configurable.
* Add content cache tests.
* 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
bhartnett
Kim De Mey