tests: add decision flow test (#4384)

* ✨ (Vector Store.spec.ts): Update test to skip if required environment variables are not set and improve test flow for Vector Store RAG test.

* ✨ (Vector Store.spec.ts): Update variable name from 'control' to 'Control' for better clarity and consistency
📝 (decisionFlow.spec.ts): Refactor test case to skip if OPENAI_API_KEY is not provided and improve code readability and maintainability by restructuring and commenting out unnecessary code blocks

* 📝 (Vector Store.spec.ts): Comment out unnecessary test.skip blocks and unused code to improve code readability and maintainability.

* refactor: update test to click on "New Flow" instead of "New Project"

* ✨ (store-shard-2.spec.ts): Refactor test to use a reusable function for clicking elements and waiting for visibility to improve code readability and maintainability
🔧 (deleteFlows.spec.ts): Refactor test to use separate functions for waiting for and interacting with elements to improve code readability and maintainability