[Feature] Allow specifying path to the home rc file #7296

• I'd be willing to implement this feature (contributing guide)
• This feature is important to have in this repository; a contrib plugin wouldn't do

Describe the user story

Being able to specify path to the home rc file can make yarn more configurable. It's often useful to isolate a tool. Maybe one don't want their home directory to be messy. Or maybe one is borrowing someone's computer and don't want to accidentally change anything, or accidentally affected by the original config.

Describe the solution you'd like

A method to specify the path to the home rc file when running the yarn command.

An alternative can be moving the file into globalFolder, and then the folder can be specified with environment variables.

Describe alternatives you've considered

Configuring with environment variables. However, one won't be able to use yarn config set. And it won't prevent yarn being affected by a rc file that's already present.