[2D] Fails to load sprite in Sprite Editor, when removing and reinstalling 2D sprite package while the sprite editor window is open.

Steps to repro:
1. Create new project
2. Window > Package Manager > 2D Sprite > Install.
3. Import any texture and select in project window.
4. Inspector> Texture Type > Sprite > Apply.
5. Open Sprite Editor.
6. Window > Package Manager > 2D Sprite > Remove > Install.
7. Project window > Sprite > Inspector > Sprite Editor.

Actual Result:
Sprite editor window appears blank.

Expected Result:
Sprite appears in the Sprite Editor Window.

Environment:
Windows and Mac

Occurring with:
2019.2.0a13, 2019.2.0a7

Working with:
2019.2.0a6, 2019.1.0f2

Note: 2D sprite package is introduced in 2019.2.0a7