[Feature]: Add forge folder path environment variable

[dougg0k]

1. Why Do You NEED This Feature?

I'd rather if this folder was in another place, like ~/.config.

But even ~/.forge would already be better, if by default.

However a path for anyone to choose, would be better.

2. What Is NOT Possible Right Now?

Change the folder into a different location.

Currently is generated at ~/forge

3. What WILL Be Possible With This Feature?

Change the default folder path.

Proposed Solution (User Experience)

FORGE_FOLDER_PATH=/home/user/.forge

Feature Category

CLI/UX

Priority/Impact

Medium - Would be nice to have

Pre-submission Checklist

• I have searched existing issues and confirmed this is not a duplicate
• I am willing to submit a PR to implement this feature

[tusharmath]

related #1330