[Malleability] Fix ID misuse in UnicastConfigEntity type

[UlyanaAndrukhiv]

Context

The current UnicastConfigEntity type has the implementation of Entity on it. Review the UnicastConfigEntity type to check that ID() method is being used and if so confirm that its ID() returns unique hash of all the content of UnicastConfigEntity according to encoding rlp rules.

Definition of done

1. Check usages of the ID() method.
2. All structure fields are verified to be included in the hash.
3. Make sure all tests work as expected.

[UlyanaAndrukhiv]

Moved this issue to [EPIC] Refactor herocache/mempool package because UnicastConfigEntity is internally used by the cache and misused ID() to be compatible with herocache.