[Feature Request] Start directory for Load Configuration

Curent behavior

We have 1 option for this in Settings/Directory:

Configs:
Set the start directory for menu configuration browser

But that description is not really all it does, it kinda secretly does 2 things at the same time:

• Sets where the core overrides/configs/shaders are located.
• Sets as a start directory for the Load Configuration browser.

Expected behavior

I would like to separate those 2 behaviors into 2 different Directory settings to distinguish RetroArch's main config files from Core files:

RetroArch Configs:
Sets as a start directory for the Load Configuration browser. (Where you manually load main RetroArch config files)

Core Configs:
Sets where the core overrides/configs/shaders are located.

This means I could have a folder with multiple RetroArch configs neatly named and organized in a folder, and not have to go looking for it every time I go into Load Configuration because it starts in the core configs folder.

Start by tracing the Settings/Directory entry for the current Configs path and the Load Configuration browser. Determine where the same directory value is used for core overrides/configs/shaders and for browsing RetroArch config files. Done means separate settings control those two locations independently.