open_folder as util

[w-e-w]

Description

extract the open_folder in ui_common.create_output_panel as a util so it can be resues by extensions

I've seen several instances of extensions needing the same open_folder function but couldn't reuse the one in webui because it's in create_output_panel, they endend up haveing to essentially copy and paste and create a new function

I import the modules at function level and not module level because feel especially gradio import would cause issues

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests