baseline Adk a2a mcp integration

[Ruthvik-1411]

Resolves: #43
Changelog:

1. ADK root agent with access to simple tools like time and calculator.
2. Custom mcp server for arxiv research paper exploration. Added as a tool to root agent.
3. Remote ADK agent with google search tool.
4. Task manager for remote adk agent to expose it using A2A protocol.
5. Client functions inside the root agent to discover and communicated with remote agent and request responses.
6. Response manager for root agent to handle session management and response handling.
7. Simple ui that acts as proxy for frontend to handle user messages and session management. Has option to view all events during a response generation.

TODO:

1. Use logging
2. Fix linting
3. Code debts and optimization.
4. Add file system mcp server for local changes. (As a part of another pr if not possible in this)