Angular File Tree major version upgrade

[1000TurquoisePogs]

We have some limitations in the angular file tree (used within the Editor but free to use elsewhere too) which we need to overcome. In doing so, here are some expected improvements we will see:

• Performance improvements when handling very large number of files, folders, or datasets. The file tree Prime 6 component we use is slow, no longer supported, and feature-lacking. We should take advantage of Prime 12 for Angular 12, or at least Prime 10
• Potential features: Better sorting, quicker "quick" search bar, better built-in keyboard navigation, and drag and drop

[1000TurquoisePogs]

@DivergentEuropeans if you see new features that you think we could do here, please add a description.

[DivergentEuropeans]

File Tree refers to the https://github.com/zowe/zlux-file-explorer repo