[feat] PydanticAI extension

[shylee2021]

Description

Add PydanticAI extension in hyperpocket

Tasks

• Add PocketPydanticAI extension.
• Add test code
• Add example
• Add document

Example

from hyperpocket_pydanticai import PocketPydanticAI

pocket = PocketPydanticAI(tools=[
    "https://github.com/vessl-ai/hyperpocket/tree/main/tools/slack/get-message",
    "https://github.com/vessl-ai/hyperpocket/tree/main/tools/slack/post-message",
])
# get pydantic-ai compatible tools from pocket
tools = pocket.get_tools()

# get agent 
agent = Agent(
    "openai:gpt-4o",
    system_prompt="You are a slack messaging assistant. You can help the user by calling proper tools",
    tools=tools,
)