Auto create asset library in custom folders

Since Blender got ASSET LIBRARY support in 4.2, the default asset browser is tagged like NOT EDITABLE, what it means that users need to duplicate brushes (4.3 and above) and other types of data and save it to a custom folder, what is a annoying thing, since this is a manual process and need to be done brush by brush.

So the better approach to this is:

1. When blender detect a PORTABLE folder and user makes changes like toggle a option like FRONT FACES ONLY, a copy of the brush is created inside of this folder, since the idea of portable is keep things together, this will make move the folder along other computers.

2. When there is no PORTABLE folder, and the the application version is running for the first time, Blender should ask if the user want to create a folder under DOCUMENTS folder or a custom path, also ask if the user want to import things from these folders, case they already exist.

In both cases, copy the default brushes inside the application to this folder and make them editable will make things a little bit easier, since there is no need to duplicate a asset and assign a custom hotkey to a custom brush.