support deploy TiDB X using reserved resource

## Feature Request

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

TiDB X Premium Reserved is a Premium deployment shape. It should retain the Premium product capability set, while using a different resource and deployment scope from standard Premium.
In Premium Reserved, resources are fixed when the cluster starts. TiDB-worker, TiKV-worker, and coprocessor-worker are not scaled on demand. This means background tasks cannot assume that extra worker resources will be created automatically when task demand increases.
**Describe the feature you'd like:**

we wound need some way to differenciate premium and premium reserved.
background tasks like add-index and import-into cannot auto cal resource in premium reserved, we need to allow user to config them manually to control resource usage.
**Describe alternatives you've considered:**

**Teachability, Documentation, Adoption, Migration Strategy:**