When debugging, remember script arguments on a per-script, not per-workspace/folder basis

Summary of the new feature

When one debugs a PowerShell script with the "PowerShell Launch Current File w/Args Prompt" configuration:

        {
            "type": "PowerShell",
            "request": "launch",
            "name": "PowerShell Launch Current File w/Args Prompt",
            "script": "${file}",
            "args": [
                "${command:SpecifyScriptArgs}"
            ],
            "cwd": "${file}"
        },

the input field is pre-filled with the most recent arguments input on the previous debug session, whatever script from the current workspace/folder was being debugged at that time.

It would be useful to have the pre-filling done with the most recent arguments for the currently debugged script.

IOW, the arguments should be remembered separately for each script in the workspace/folder.

This would make debugging several scripts in the same workspace/folder easier.

Start from the PowerShell Launch Current File w/Args Prompt configuration and the SpecifyScriptArgs input described in the issue. Trace where the most recent arguments are stored and make the remembered value depend on the currently debugged script rather than the workspace or folder. Done means each script in a workspace pre-fills its own most recently entered arguments.