What would you like to be added?

1. Split Syncer as Agent in user cluster, and support two modes:
   1.1 Agent in user cluster watch hub cluster custom resources like syncrule, and sync info into es directly. In this mode, hub cluster will not invade the user cluster.
   1.2 Syncer in hub cluster will dispatch crds and custom resources into user cluster, and Agent in user cluster watch self apiserver. in this mode, Agent completely self-looping within the user cluster, and sre could deploy Agent independently.

2. Support more kubernetes versions.

Why is this needed?

1. Syncer takes up too much memory resource as the number of clusters increases, so a high availability solution is urgently needed.

2. Better compatibility.