Add Apply to Selected to Facility Shading tab Construction and Schedule columns

[Ski90Moo]

Summary

• Enables the "Apply to Selected" button on the Construction Name and Transmittance Schedule Name columns of the Facility Shading tab
• The showColumnButton flag was false for both drop zone columns; changed to true to match the pattern used by other tabs

Closes #882

Test plan

• Open a model with multiple shading surface groups
• Navigate to Facility tab → Shading subtab
• Select multiple rows using the checkboxes
• Click a cell in the Construction Name or Transmittance Schedule Name column
• Verify the "Apply to Selected" button appears and applies the value to all selected rows

[macumber]

Let's wait on this for RC2