Add MRU to argument prompt when debugging a PowerShell script

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.

It would be useful to have a list of most recently used argument lists, so that one could easily test the same script with several sets of arguments.

Proposed technical implementation details (optional)

The list should be sorted by most-recently used argument list.

Start with the PowerShell Launch Current File w/Args Prompt configuration and the ${command:SpecifyScriptArgs} input described in the issue. Trace how the prompt is populated and determine where its recent argument lists are handled. Done means the prompt offers previously used argument lists in most-recently-used order.