Refactor stress test to use smoke test general config

[lumtis]

Stress tests have been commented out in https://github.com/zeta-chain/node-private/pull/81

The reason is that the code is not adapted to the new structure. We introduce a general config for the smoke tests containing list of RPCs.

There are also other breaking changes introduced in the PR above: separation of setup from the actual smoke tests

We should refactor the stress test codebase to use this config and reenable it back.