feat: support the class-name as override value

[ryanzhang-oss]

Description of your changes

support the ${MEMBER-CLASS-NAME} as an override value

Fixes #

I have:

• Run make reviewable to ensure this PR is ready for review.

How has this code been tested

Special notes for your reviewer

[Copilot]

Copilot reviewed 5 out of 11 changed files in this pull request and generated no comments.

Files not reviewed (6)

• pkg/controllers/workgenerator/override.go: Evaluated as low risk
• pkg/controllers/workgenerator/override_test.go: Evaluated as low risk
• test/e2e/actuals_test.go: Evaluated as low risk
• test/e2e/placement_ro_test.go: Evaluated as low risk
• pkg/controllers/workgenerator/controller.go: Evaluated as low risk
• pkg/utils/overrider/overrider.go: Evaluated as low risk

[Copilot]

Copilot reviewed 5 out of 13 changed files in this pull request and generated 1 comment.

Files not reviewed (8)

• apis/placement/v1alpha1/common.go: Evaluated as low risk
• apis/placement/v1alpha1/override_types.go: Evaluated as low risk
• apis/placement/v1alpha1/zz_generated.deepcopy.go: Evaluated as low risk
• pkg/controllers/workgenerator/controller.go: Evaluated as low risk
• pkg/controllers/workgenerator/override.go: Evaluated as low risk
• pkg/utils/overrider/overrider.go: Evaluated as low risk
• test/e2e/placement_apply_strategy_test.go: Evaluated as low risk
• pkg/utils/overrider/overrider_test.go: Evaluated as low risk

Comments suppressed due to low confidence (2)

test/e2e/actuals_test.go:125

• The comment should be 'config map' instead of 'config map'.

// config map

test/e2e/actuals_test.go:119

• Ensure that the function configMapPlacedOnClusterActual is covered by tests to verify its behavior.

func configMapPlacedOnClusterActual(cluster *framework.Cluster, wantConfigMap *corev1.ConfigMap) func() error {