JSON encoding of `returnValue` field in the EVM Logger

[s1na]

It was reported in NethermindEth/nethermind#8186 that in the EVM logger geth returns returnValue (the return data of the top call) as non-prefixed hex string. This seems wrong. It has been there forever and tooling depends on it I imagine so it is an unfortunate situation. At risk of angering people IMO we should add the hex prefix. It is not a big change for users.

[Pyakouto]

My funds

[s1na]

Triage discussion: we will fix it

cc @wurdum