[Internal] Rollout Plugin Framework

[edwardfeng-db]

Changes

• Made it possible to use environment variable USE_SDK_V2 to control rollout
• Bumped resource and data source names from staging names to production names (can debate on whether we want to do that now or in a more gradual fashion)
• Proposed mechanism: https://docs.google.com/document/d/1zfTp8YesMe4GxkbIt9Sbwd5nQL7Y4mXed8dPDGmAoxU/edit?tab=t.0
• Added infra for switching providers from sdkv2 to plugin framework in integration tests and added test cases for those cases

Tests

• [x] make test run locally
• [x] relevant change in docs/ folder
• [x] covered with integration tests in internal/acceptance
• [x] relevant acceptance tests are passing
• [x] using Go SDK

[eng-dev-ecosystem-bot]

Test Details: go/deco-tests/11622757764