Listing a dataset can hang

[gejohnston]

List dataset hangs after an uninstall & new connect in ZE extension.

Start with a working backend already installed.

• Zowe-SSH: Uninstall Zowe Server from Host...
• Zowe-SSH: Connect to Host...
• Magnifying Glass in Data Sets tree
• Select a dataset pattern
• The progress bar displays continually with no end.
• Use VS Code menu to Reload Window.
• Search for the dataset pattern again
• Everything displays fine.

We should not put the user in a position to have to reload the window.

Describe your environment

Additional context