This commit introduces comprehensive unit tests for critical functions in the `apiclient` package, specifically within `wait.go`. These tests are designed to ensure the reliability and correctness of various waiter functions that are essential for monitoring and managing Kubernetes control plane components.

### Added Tests:
1. **TestGetControlPlaneComponents**: Validates the `getControlPlaneComponents` function by checking that it correctly constructs control plane component URLs based on configuration inputs.
   
2. **TestGetStaticPodSingleHash**: Ensures that `getStaticPodSingleHash` retrieves the correct hash value from pod annotations.

3. **TestGetStaticPodSingleHash_PodNotFound**: Verifies that `getStaticPodSingleHash` returns an appropriate error when the specified pod does not exist.

4. **TestWaitForStaticPodSingleHash**: Confirms that `WaitForStaticPodSingleHash` waits for and retrieves the correct hash value for a static pod.

5. **TestWaitForPodsWithLabel**: Checks that `WaitForPodsWithLabel` only returns successfully when all pods with a specific label are in the `Running` phase, simulating different pod states.

6. **TestWaitForStaticPodHashChange**: Validates that `WaitForStaticPodHashChange` accurately detects changes in the hash of a static pod, which is critical for determining if the pod has been restarted.

7. **TestWaitForStaticPodHashChange_Timeout**: Ensures that `WaitForStaticPodHashChange` times out appropriately if the pod hash does not change.

8. **TestWaitForStaticPodControlPlaneHashes**: Verifies that `WaitForStaticPodControlPlaneHashes` successfully retrieves hashes for all control plane static pods.

### Implementation Notes:
- **Mock Kubernetes Client**: These tests use `client-go/fake` to simulate interactions with the Kubernetes API server, allowing for isolated and predictable testing without requiring an actual cluster.
- **HTTP Server Simulation**: `httptest` is used to create mock HTTP responses for the health endpoints, testing the HTTP polling logic in functions like `WaitForControlPlaneComponents` and `WaitForAPI`.
- **Timeout Handling**: All tests are written with specific timeouts to avoid hanging indefinitely. Short timeouts are used in certain cases to simulate realistic polling intervals.

These tests enhance the robustness of the `apiclient` package by ensuring the core waiter functions handle expected scenarios and edge cases effectively. The coverage gained by these tests will assist in catching regressions and improve confidence in code modifications going forward.

This commit introduces comprehensive unit tests for critical functions in the `apiclient` package, specifically within `wait.go`. These tests are designed to ensure the reliability and correctness of various waiter functions that are essential for monitoring and managing Kubernetes control plane components.

### Added Tests:
1. **TestGetControlPlaneComponents**: Validates the `getControlPlaneComponents` function by checking that it correctly constructs control plane component URLs based on configuration inputs.
   
2. **TestGetStaticPodSingleHash**: Ensures that `getStaticPodSingleHash` retrieves the correct hash value from pod annotations.

3. **TestGetStaticPodSingleHash_PodNotFound**: Verifies that `getStaticPodSingleHash` returns an appropriate error when the specified pod does not exist.

4. **TestWaitForStaticPodSingleHash**: Confirms that `WaitForStaticPodSingleHash` waits for and retrieves the correct hash value for a static pod.

5. **TestWaitForPodsWithLabel**: Checks that `WaitForPodsWithLabel` only returns successfully when all pods with a specific label are in the `Running` phase, simulating different pod states.

6. **TestWaitForStaticPodHashChange**: Validates that `WaitForStaticPodHashChange` accurately detects changes in the hash of a static pod, which is critical for determining if the pod has been restarted.

7. **TestWaitForStaticPodHashChange_Timeout**: Ensures that `WaitForStaticPodHashChange` times out appropriately if the pod hash does not change.

8. **TestWaitForStaticPodControlPlaneHashes**: Verifies that `WaitForStaticPodControlPlaneHashes` successfully retrieves hashes for all control plane static pods.

### Implementation Notes:
- **Mock Kubernetes Client**: These tests use `client-go/fake` to simulate interactions with the Kubernetes API server, allowing for isolated and predictable testing without requiring an actual cluster.
- **HTTP Server Simulation**: `httptest` is used to create mock HTTP responses for the health endpoints, testing the HTTP polling logic in functions like `WaitForControlPlaneComponents` and `WaitForAPI`.
- **Timeout Handling**: All tests are written with specific timeouts to avoid hanging indefinitely. Short timeouts are used in certain cases to simulate realistic polling intervals.

These tests enhance the robustness of the `apiclient` package by ensuring the core waiter functions handle expected scenarios and edge cases effectively. The coverage gained by these tests will assist in catching regressions and improve confidence in code modifications going forward.