[Bug] Escape key does not dismiss the sidebar

[iamkartiknayak]

Issue/Description:
Pressing the Escape key while the sidebar is open does not close or dismiss it.

Version:

 cosmic-edit:
  Installed: 0.1.0~1763995212~24.04~10f1b8d

Steps to Reproduce:

• Open the settings in COSMIC Edit
• Press the Escape key
• Observe that the sidebar remains open

Expected Behavior:
The Escape key should close/dismiss the sidebar when it is active like how it's implemented in Files & Terminal