Supporting user-defined kubelet directory

[lynn901]

• Make sure you have followed Kube-OVN Code Style.

What type of this PR

Examples of user facing changes:

• Bug fixes

Which issue(s) this PR fixes:

Fixes #2047

WHAT

🤖 Generated by Copilot at 5817053

This pull request adds a new feature to customize the kubelet directory for the ovn-cni daemonset, which is useful for DPDK-based network interfaces. It modifies the ovncni-ds.yaml chart template, the config.go and handler.go files in the pkg/daemon package, and the corresponding Linux and Windows handlers. It also adds a new command-line flag kubelet-dir for the daemon component.

🤖 Generated by Copilot at 5817053

Sing, O Muse, of the cunning ovn-cni daemonset
That brought to many pods a swift and smooth network
By creating short links for the vhostuser sockets
With createShortSharedDir, a skillful function.

HOW

🤖 Generated by Copilot at 5817053

• Add a new flag --kubelet-dir to the ovn-cni daemonset container, which allows specifying the path of the kubelet directory (link)
• Replace the hard-coded path /var/lib/kubelet/pods with the value of the kubelet-dir flag in the ovn-cni daemonset container, which is passed as a Helm value (link)
• Add a new field KubeletDir to the Configuration struct in pkg/daemon/config.go, which stores the value of the kubelet-dir flag (link)
• Parse the kubelet-dir flag from the command-line arguments and set the default value to /var/lib/kubelet in the ParseFlags function in pkg/daemon/config.go (link, link)
• Use the KubeletDir field of the Configuration struct to construct the origin and new shared directories for the vhostuser socket volume in the createShortSharedDir function in pkg/daemon/handler_linux.go (link, link)
• Add loops to check if the origin and new shared directories exist, and wait for up to 20 seconds if not, in the createShortSharedDir function in pkg/daemon/handler_linux.go (link, link)
• Add the time package to the imports of the pkg/daemon/handler_linux.go file, which is needed for the loops (link)
• Add the KubeletDir field of the Configuration struct to the arguments of the createShortSharedDir function in the handleAdd function in pkg/daemon/handler.go, which is responsible for creating a short symbolic link for the vhostuser socket volume of the pod (link)
• Add the kubeletDir parameter to the signature of the createShortSharedDir function in pkg/daemon/handler_windows.go, which is a dummy function that does nothing on Windows, to keep the function signature consistent with the Linux version (link)

[zbb88888]

I'm not sure about the yaml, please help check @hongzhen-ma