Live Market Data Ribbon Controls

Problem Description

A portfolio management team wants a PyXLL ribbon to control live market data in their Excel workbook. The "Market Data" tab should contain:

1. A toggle button to enable or disable live streaming (the button must reflect its current on/off state — the ribbon should show whether streaming is active)
2. A dropdown to select the data provider: Bloomberg, Reuters, or Internal
3. A "Refresh Now" button to force an immediate data pull

When the user switches data provider, the ribbon controls should be refreshed to reflect any state changes (e.g. some providers may affect which other controls are enabled).

Output Specification

Produce two files:

• portfolio_ribbon.xml — complete ribbon XML for the Market Data tab
• portfolio_ribbon.py — Python module with full callback implementations for all controls. Stub out any business logic with pass or a print statement, but implement the function signatures correctly and include the mechanism for refreshing ribbon controls after a provider change.