Poll smart-contract transaction logs directly from the REST Mirror Network

[3Nigma]

Currently, we issue a TransactionRecordQuery request if we want smart-contract execution logs following a ContractExecuteTransaction call. For ContractCallQuery there is no such requirement since, by design, the ContractCallQuery response (which is a ContractFunctionResult) contains those logs.

Such a transaction is costly but there is a way around this: we poll for the logs from the mirror-node via GET-ing on /api/v1/contract/{contractId}/results/logs.

Now this is admittedly a burdensome strategy since it will put load on the mirror-node, yet since other libraries are doing it (eg. hethers), we might as well go down this path for cost-efficiency. Maybe we have this polling enabled via a flag? That's worth thinking about.

[3Nigma]

TransactionReceipts can also be sufficiently reconstructed from rest-mirror fetched data so we should include them as well.

A new StratoContext - network config parameter shall be introduced, HEDERAS_REST_MIRROR_URL, that will be used if HEDERAS_NETWORK is customnet and the default value of http://127.0.0.1:5551 will not suffice.

Following this transition to rest-mirror data, the following session parameters will be no longer needed and subsequently removed:

• HEDERAS_DEFAULT_EMIT_CONSTRUCTOR_LOGS (and other network variants)
• HEDERAS_DEFAULT_EMIT_LIVE_CONTRACTS_RECEIPTS (+ specific network variants)
• HEDERAS_DEFAULT_CONTRACT_REQUESTS_RETURN_ONLY_RECEIPTS (+ variants)