Tiup support to deploy VM to replace prometheus in some scenarios

[qqqdan]

Feature Request

Is your feature request related to a problem? Please describe:

Describe the feature you'd like:

User can use TiUP to deploy VM (https://docs.victoriametrics.com/) to replace prometheus

• VM agent can be auto deployed during cluster scale in scale out
• VM can use the existing configuration of metrics

Why the featue is needed:

When there are 100+ nodes in the TiDB Cluster ,the prometheus may have bad performance, in this case, we can provide VM to replace prometheus

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: