[Feature Request] RunContext does not have tool_call_id

[RayneSun]

Problem Description

When tools yield CustomEvent objects, there's currently no way to access the tool_call_id within the tool function to include it in the event. This makes it impossible to correlate CustomEvent with their corresponding ToolCallStart events, especially when the model calls multiple tools in parallel.

Proposed Solution

Add tool_call_id as a built-in parameter to RunContext, similar to existing parameters like session_state, dependencies, and metadata.

Suggested implementation:

from agno.run import RunContext
from agno.run.agent import CustomEvent
from agno.tools import tool
from dataclasses import dataclass

@dataclass
class MyCustomEvent(CustomEvent):
    tool_call_id: str
    progress: str

@tool
async def my_tool(run_context: RunContext):
    # Access tool_call_id directly from run_context
    tool_call_id = run_context.tool_call_id
    
    yield MyCustomEvent(
        tool_call_id=tool_call_id,
        progress="Processing..."
    )

### Alternatives Considered

_No response_

### Additional Context

_No response_

### Would you like to work on this?

- [x] Yes, I’d love to work on it!
- [ ] I’m open to collaborating but need guidance.
- [ ] No, I’m just sharing the idea.

[RayneSun]

RunContext should give more to functions, sometimes function need to read run_messages!