feat: optimize memory and apiserver use

[jmclong]

This pull request introduces several improvements and refactorings to the CSI driver, focusing on simplifying event recording, improving cache configuration, and cleaning up event emission logic. The most significant changes include refactoring how the driver's Pod is referenced for event logging, updating cache and client options for better performance and correctness, and removing unnecessary or redundant event emissions in the LVM code.

Refactoring event subject and context:

• The driver's Pod is now constructed at startup from downward-API environment variables and passed explicitly to components that need it, rather than being fetched from the API server. This simplifies event emission and ensures that events are always associated with the correct Pod. (cmd/driver/main.go, internal/csi/controller/controller.go, internal/csi/core/lvm/startup.go) [1] [2] [3] [4] [5] [6] [7]

Kubernetes cache and client configuration:

• The controller-runtime manager's cache and client options are updated to use TransformStripManagedFields and to disable caching for certain objects (like CSIDriver and Node), improving efficiency and correctness. (cmd/driver/main.go, cmd/manager/main.go) [1] [2]

LVM event emission cleanup:

• Several event emissions related to provisioning and deleting logical volumes and volume groups are removed to reduce noise and redundancy. Only essential events (such as failures or empty volume creation) are now emitted. (internal/csi/core/lvm/lvm.go, internal/csi/core/lvm/controller.go) [1] [2] [3] [4] [5] [6] [7]

Pod UID propagation and downward-API usage:

• The DaemonSet YAML and driver startup logic now propagate the Pod UID via environment variable and command-line argument, enabling accurate Pod object construction for event emission. (charts/latest/templates/daemonset.yaml, cmd/driver/main.go) [1] [2] [3] [4] [5]

Resource limits adjustment:

• The memory limit for the manager is increased from 128Mi to 500Mi to accommodate higher resource usage. (charts/latest/values.yaml)