Tracking: Watermark

[TennyZhuang]

RFC PR: risingwavelabs/rfcs#2 Implementation design doc: https://github.com/risingwavelabs/rfcs/blob/46123694776083788a08b880ab1fa27eda542b76/rfcs/0016-watermark-operators-explained.md

• Source
  • [x] #6952
• Frontend
  • [x] #6704
  • [x] #6070
  • [x] Derive watermark columns
  • [x] #6452
• Stream
  • [x] #6043
  • [x] #6046
  • [x] #6060
  • [x] #6050
  • [x] #8444
  • [x] Watermark derivation in window functions
  • [x] #6268
  • [x] #6472
  • [x] #6112
  • [x] #8106
  • [x] #6813
  • [x] #7811
  • [x] #8375
  • [x] #10618
  • [x] #10619
  • [ ] #10620
  • [x] #10621

[TennyZhuang]

After some discussions, we can also clean the state in DynamicFilter executors.

[tabVersion]

will we handle watermark events from the upstream in CDC scenes?

[hengm3467]

@TennyZhuang Do you think we can prepare external docs about watermark?