feat(kvstore): add storage_type support for Redis 7.0 cloud-disk inst…

[cxx-12333]

Summary

Add storage_type field to alicloud_kvstore_instance resource to support
Redis 7.0 cloud-disk instances.

Problem

Redis 7.0 requires cloud-disk instance classes and the StorageType parameter
must be passed to the CreateInstance API. Without this field, users get:
EngineVersion.NotSupportOnLocalDisk

Changes

• Schema: add storage_type (Optional, ForceNew, Computed)
  Valid values: cloud_essd, cloud_essd_pl1, cloud_essd_pl2, cloud_essd_pl3
• Create: pass StorageType to CreateInstance API
• Read: populate storage_type from DescribeInstances response

Usage

resource "alicloud_kvstore_instance" "redis_7" {
  instance_type  = "Redis"
  engine_version = "7.0"
  instance_class = "redis.master.small.cloud.default"
  storage_type   = "cloud_essd"
  ...
}

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[xuzhang3]

@cxx-12333 Thank you for submit this PR. Current KV store resource is using the API:https://next.api.aliyun.com/api/R-kvstore/2015-01-01/CreateInstance while StorageType is being supported in https://next.api.aliyun.com/api/R-kvstore/2015-01-01/CreateTairInstance, there are two different API.
And also ensure the AccTest can pass.