[Possible] Broadcast fee too low - both "accepted" and "invalid"

[alexbarnsley]

Describe the bug
I'm not sure if this is an issue or not after speaking to @faustbrian. If the minBroadcastFee is set high, it's possible for the node receiving the transaction to accept it. It's also possible for the transaction to be invalid because it's not able to broadcast. The question is, should it be both accepted and invalid at the same time?

[faustbrian]

We should probably change the logic at https://github.com/ArkEcosystem/core/blob/develop/packages/core-transaction-pool/src/guard.ts#L124-L135 and only return an error for a transaction if both fail.

@supaiku0 thoughts?

[faustbrian]

I think we should also use 2 distinct error codes rather then simply ERR_LOW_FEE for both scenarios. The client won't be able to know what failed unless he checks the accompanying message.

[zillionn]

IMO if accepted OR broadcasted shouldn't be invalid.