DWO Stress Testing

[dkwon17]

Description

Create load tests for the DevWorkspace operator.

Load tests should be done before every DWO release.
Load tests should help us observe the controller's CPU and memory usage for 1000-1500 concurrent workspaces
Load tests should create automount configmaps and secrets to test its effect on memory usage

Additional context

For example for the Eclipse Che project we have: https://github.com/eclipse-che/che/tree/main/tests/performance/load-tests

Related investigations done in the past:

• Figure out how DevWorkspace operator / webhooks server responds to heavy load #398
• Limit objects cached by DevWorkspace controller to reduce memory usage #652