File Chooser interface is not user friendly on the large sites

[hissy]

Description

One of our clients has a huge size of file manager, and the new file chooser interface introduced in version 9 is not a good change for them. There are a couple of problems.

1. Clicking the file manager link in the file chooser interface will always fetch the root folder. It's annoying if you select a folder in the big folder tree. Why can't we keep the selected folder?
2. Loading options in the upload folder pulldown menu take too much time to fetch. It doesn't show all folders, even if it takes a long time to fetch all directories.

Example

I think there are some improvements we can.

1. Do not load a root folder every time you click the file manager link. We should reload only after uploading a file.
2. I know some people love keyword filtering, but other people don't. How about adding an option to use fancytree interface to pick a folder?

[webpresso-ch]

Like the suggestions very much.
We have the same issues with our clients.

[hissy]

Related issue #12115