Add a label field in topology template for node label

[qqqdan]

Feature Request

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

Describe the feature you'd like:

In DR failover scenario, in a big cluster, some nodes are primary node, some nodes are secondary node, we need a label to distinguish them . This label can be also used in other scenarios.

Why the featue is needed:

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: