Existing tests are rewritten to be run with k6

[flavio]

The existing tests are written using locust, we want to migrate to k6. k6 will allow us to correlate the CPU/Memory usage with the load generated by the tests. k6 is an open source project from Grafana, hence it nicely integrates with the prometheus + grafana stack that Kubewarden already supports.

During the migration process all the exists tests should not be lost.

This branch contains some code that can be used to perform load tests using k6.

Acceptance criteria

• All the current tests are rewritten using k6 scripting language