feat: Add support exporting Prometheus metrics

[hayk96]

1. What this PR does / why we need it:

• This PR adds support exporting Prometheus metrics for both: Sync and DNS components
• The following metrics have been introduced:
  • kubebridge_sync_services - Total services discovered and synchronized by the KubeBridge Sync component
  • kubebridge_sync_services_count - Number of services synchronized by the KubeBridge Sync component
  • kubebridge_dns_requests - Total count of DNS requests processed for domain records
  • kubebridge_dns_lookup_time_seconds - Time taken to resolve DNS queries in seconds
• The multiprocessing mode has been replaced with the multithreading for handling the correct export of metrics as the separate processes have separate memory space
• Added commonPodAnnotations key in the Helm chart to allow scrapping Prometheus metrics

2. Make sure that you've checked the boxes below before you submit PR:

• DCO signed
• No conflict with the main branch.
• Version updated in code, docs, and metadata.