Refresh method for FileExplorer component

[DRomatzki]

• I have searched to see if a similar issue already exists.
  Yes, Even tried a custom FileExplorer but could not get the "refresh" solved.

Describe the solution you'd like
A file explorer component shows the local file structure, but sometimes the underlying file structure changes due to file addition, renaming and deletion. So there must be a way to toggle a refresh.

Additional context
Currently I am overcoming the refresh by toggling the "glob" or "ignore_glob" parameters in the traditional way with success, but it would be nice to have a refresh parameter/method. Looking at the source code of the FIleExplorer is could be done by adding a refresh flag to the [Key] trigger list. The problem is I can not figure out the part thereafter and how the [key] are used to update the interface.

[freddyaboulton]

This is related to #7788 imo. We can either refactor the component to refresh automatically or add a method to trigger the refresh.