Minimum horizontal width is not set for Packages name list and description divider in Packman window. Refer the attached video

Steps to reproduce:
1) Create a new project
2) Window > Package Manager
3) Drag horizontally the divider between Packages and description

Actual Result: Minimum horizontal width is not set for the divider and Packages name list and description both get clipped

Expected Result: Minimum horizontal width should be set for both Packages name list and description so that they don't get clipped

Occurring on: 2020.1.0a13, 2020.1.0a1, 2019.3.0b12

Not Reproducible on: 2019.3.0b11

Environment: Both Windows and Mac