feat: Numaflow API v1.1 initial commit

[jy4096]

• Add v1_1 handler pkg (a copy and paste from v1)
  • add ListClusterSummary
  • TODO: missing handlers
• Add v1_1 router
• Add v1_1 common response data type
  • TODO: detailed response data type for each API call

TODO: replace v1 with v1_1

Please refer to internal API design doc for more info.

[vigith]

do we really need v1_1 since we are working on the same branch and/also UI server and UI are in the same image?

[vigith]

let's make sure we will remove v1_1 when we merge to the main branch.