fix(kubernetes): consider workload not ready when scaled to 0 (#543)

* test(kubernetes): use testcontainers for test

* fix(kubernetes): get state properly reports the workload as down when scaled to 0

* refactor(kubernetes): split provider in multiple files

* refactor(provider): use Instance prefix for actions

* test(testcontainers): use provider.PullImage

* squash

* Revert "test(testcontainers): use provider.PullImage"

This reverts commit 6f958c48a5.

* test: add random generator thread safety

pkg/provider/docker/container_list_test.go

@@ -103,7 +103,7 @@ func TestDockerClassicProvider_GetGroups(t *testing.T) {
 	i2, err := dind.client.ContainerInspect(ctx, c2.ID)
 	assert.NilError(t, err)
 
-	got, err := p.GetGroups(ctx)
+	got, err := p.InstanceGroups(ctx)
 	assert.NilError(t, err)
 
 	want := map[string][]string{