Feat/sdk targeted list limits (list-limits part of issue #1107)

[J-Nad]

Summary

This PR adds targeted list-limit updates to the Python SDK as the Python counterpart to the existing Node SDK changes.

Previously, changing a robot's limit through the SDK meant updating and resending the workflow. With this change, the SDK can send only the specific limit that needs to be updated.

What changed

• Added Robot.set_list_limit() as the higher-level method for updating a robot's limit.
• Supports scrapeList, crawl, and search actions.
• The method searches the robot workflow for the first matching action containing a limit and determines its pairIndex, actionIndex, and argIndex automatically.
• Added Client.update_list_limits() for sending one or more targeted limit updates directly.
• Added ListLimitUpdate typing for the targeted update payload.
• Added a short usage example to the README.

Example:

robot = await extractor.get_robot(robot_id)
await robot.set_list_limit(25)

Instead of resending the full workflow, the SDK sends only the targeted update:

{
  "limits": [
    {
      "pairIndex": 0,
      "actionIndex": 0,
      "argIndex": 0,
      "limit": 25
    }
  ]
}

The backend can then update that specific value while leaving the rest of the workflow unchanged.

Related work

This is the Python SDK portion of the targeted list-limit work for getmaxun/maxun#1107.

Related PRs:

• getmaxun/maxun#1176 — adds support for targeted list-limit updates in the SDK route.
• getmaxun/node-sdk#34 — adds the corresponding functionality to the Node SDK.