Integration test for node selection

[deyanzz]

New integration tests should be added to test the node selection for:

• Node
• Client
• Executable

These tests should be executed against a working Hedera Local Node. All necessary configurations should be done also.

To fully test the backoff time when connecting to a failed node, the following task should be completed first for the Local Node:

• Support multiple nodes in the local hedera network hashgraph/hedera-local-node#120
• Improve stability of local node hashgraph/hedera-local-node#309

[deyanzz]

Currently I'm working on #201 as it's a blocker for #164. This issue is set On Hold.

[deyanzz]

I will move back to this task once PR #197 is completed.

[deyanzz]

Moving back to this issue, as the following task for Hedera Local Node have been completed:

• Support multiple nodes in the local hedera network hashgraph/hedera-local-node#120
• Improve stability of local node hashgraph/hedera-local-node#309

[deyanzz]

Currently, this task could not be tested locally, as the Hedera Local Node has some issues to be started with mode --multinode.

Testnet should be used as a preferred network for testing.