Chore/Update issue templates and add new tools (#4687)

* Enhancement: Update issue templates and add new tools

- Updated bug report template to include a default label of 'bug'.
- Updated feature request template to include a default label of 'enhancement'.
- Added new credential class for Agentflow API.
- Enhanced Agent and HTTP nodes to improve tool management and error handling.
- Added deprecation badges to several agent and chain classes.
- Introduced new tools for handling requests (GET, POST, DELETE, PUT) with improved error handling.
- Added new chatflows and agentflows for various use cases, including document QnA and translation.
- Updated UI components for better handling of agent flows and marketplace interactions.
- Refactored utility functions for improved functionality and clarity.

* Refactor: Remove beta badge and streamline template title assignment

- Removed the 'BETA' badge from the ExtractMetadataRetriever class.
- Simplified the title assignment in the agentflowv2 generator by using a variable instead of inline string manipulation.