fix: quick app windows, tray and dock behaviors

[louis-jan]

Describe Your Changes

• Keep Jan app to stay on the dock when running, even if the main window is closed. (Hidden before)
• Show Jan's app's main window when users click it in the dock or open it from a quick action.
• Click on app tray icon, quick ask window should be shown
• Should not hide main window when pressing esc

Fixes Issues

• bug: Quick ask - multiple instances remains in system tray when opened / closed Jan app multiple times and other glitchs #2305

Self Checklist

• Added relevant comments, esp in complex areas
• Updated docs (for bug fixes / features)
• Created issues for follow-up changes or refactoring needed