[Routing WG] ASOC Intern project 4: Skip kernel routes downloading

[eddieruan-alibaba]

• Add zebra policy with skip kernel insertion as an action
• Use zebra policy to set a flag in zebra route node
• use this flag to skip kernel routes insertion
• Add fpm simulate, all API params and event sequence would be stored in a file for UT.

[prgeor]

@zhangyanzhao can you take care of moving these intern project requests to sonic repo from buildimage repo?

[eddieruan-alibaba]

Wenbo's PR is at FRRouting/frr#14166