Description

Fixes various strong reference cycles throughout the app relating to either WorkspaceDocument, related window controllers, view controllers, or sub-models.

This does not entirely close # 1794. There is still some leaked outline view cells that are strongly referencing workspace files (no idea why).
After updating CESE, CodeFileDocument is no longer strongly referenced. There is still an issue with the project navigator's cells staying alive after the window closing but I think this PR is substantial enough to merge now.

Substantial changes:

• Modified the commands registry api to get rid of some unnecessary wrapping of callbacks.
• Modified the StandardTableViewCell to use the built-in label and icon properties, and adding the secondary label on top of NSTableViewCell.
• ExtensionDiscovery slightly reworked to better support cancellation of tasks.
• Changed to using performClose over close on window objects (this will animate the close button being pressed, and is what should be used in window commands).
• Added a new property wrapper: @UpdatingWindowController that weakly references and auto-updates a window controller variable. Useful in SwiftUI views or commands that need updating access to the current window controller.

Related Issues

• closes 🐞 CodeFileDocument Not Releasing Correctly #1794

Checklist

• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots

N/A. No UI changes.