create node pool for tiflash and cdc (#2413)

[sre-bot]

cherry-pick #2413 to release-1.1

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What problem does this PR solve?

fix #2376

What is changed and how does it work?

Support creating node pools for tiflash and cdc

Check List

Tests

• Manual test (add detailed scripts or steps below)
  • Deploy EKS with the following config, node pools for tiflash and cdc are created successfully and tiflash Pods can be scheduled to the tiflash nodes.

  create_tiflash_node_pool = true
  create_cdc_node_pool = true
  cluster_tiflash_count = 2
  cluster_cdc_count = 2
  cluster_cdc_instance_type = "c5.large"
  cluster_tiflash_instance_type = "c5d.large"
  

  • Deploy EKS with the following config, node pools for tiflash and cdc will not be created.

  #create_tiflash_node_pool = true
  #create_cdc_node_pool = true
  cluster_tiflash_count = 2
  cluster_cdc_count = 2
  cluster_cdc_instance_type = "c5.large"
  cluster_tiflash_instance_type = "c5d.large"
  

Code changes

• Has Terraform scripts change

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

Does this PR introduce a user-facing change?:

Support creating node pools for tiflash and cdc on EKS

[DanielZhangQD]

LGTM

[DanielZhangQD]

/merge

[sre-bot]

/run-all-tests