[VPC] Add description field in r/vpc_v1

[lego963]

Summary of the Pull Request

Add description field in resource/opentelekomcloud_vpc_v1

PR Checklist

• Tests added/passed.
• Documentation updated.
• Schema updated.
• Release notes added.

Acceptance Steps Performed

=== RUN   TestAccVpcV1_basic
=== PAUSE TestAccVpcV1_basic
=== CONT  TestAccVpcV1_basic
--- PASS: TestAccVpcV1_basic (112.61s)
=== RUN   TestAccVpcV1_timeout
=== PAUSE TestAccVpcV1_timeout
=== CONT  TestAccVpcV1_timeout
--- PASS: TestAccVpcV1_timeout (68.02s)
=== RUN   TestAccVpcV1_import
=== PAUSE TestAccVpcV1_import
=== CONT  TestAccVpcV1_import
--- PASS: TestAccVpcV1_import (83.22s)
PASS

[otc-zuul]

Build succeeded.

✔️ build-otc-releasenotes SUCCESS in 2m 40s
✔️ otc-golangci-lint SUCCESS in 2m 33s
✔️ golang-make-test SUCCESS in 2m 52s
✔️ golang-make-vet SUCCESS in 2m 20s
✔️ tflint SUCCESS in 1m 34s
✔️ goreleaser-build SUCCESS in 7m 35s