chore (postgres): Establish a testing environment and tooling to measure Store performance

[Ivansete-status]

Background

nwaku & postgres can work together when nwaku has the store protocol mounted.
In order to optimize the interaction with Postgres, we first need to have a testing tooling.

Details

Create a test project that can query a "store" node and analyze its performance.

Acceptance criteria

Have the initial test project with the essential stress test set. Of course, this project will grow over time.

• Creation of the base test project
• Test case: one single user publishes 1000 messages. All the messages should be stored properly.
  - [ ] Test case: 100 users publish 100 messages each, concurrently and each user sends 1 msg/sec. All the messages should be stored properly. Edited: that use case can't be implemented to validate Store performance because messages are dropped due to the Relay protocol (GossipSub nim-libp2p) not being able to support that high rate. For example, having 30 concurrent users publishing 300 messages concurrently will imply that a couple of messages can get lost. If we increase the number of users, then more messages can get lost.

[Ivansete-status]

@richard-ramos created the next project which is the starting point for the next stress tests to come:
https://github.com/waku-org/test-waku-query