Feature Request: Support the "env" key in launch.json for debugging Environment Variable setup

Prerequisites

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Summary

When debugging PowerShell scripts it is necessary at times to set environment variables to be used for given debug configuration.

This use-case is especially necessary when debugging scripts that are to be used in conjunction with Azure devops YAML pipelines as all pipeline variables are environment variables. Example: Where we have multiple pipeline steps emitting variables (YAML template expression "each" usage) and we use a PowerShell script to gather the outputs for processing and formatting (YAML template expression "join" used to pass parameters to the PowerShell script). Debugging this use-case is harder than it needs to be right now and suggested work arounds, whilst usable, are cumbersome.

Proposed Design

Support for an "env" key for "PowerShell" debugging as per other configuration types please, e.g.

Start by tracing how the PowerShell extension reads debugging configurations from launch.json and compare that handling with other VS Code configuration types that support env. Done means a PowerShell debug configuration can define environment variables and the launched script receives them; verify the behavior with the extension's existing debugging checks.