Support for devcontainer workspaceMount & workspaceFolder

[jonah-iden]

What it does

This adds support for workspaceMount and workspaceFolder options for devcontainer.json files

How to test

Create a devcontainer.json with content like this:

{
    "image": "mcr.microsoft.com/devcontainers/typescript-node:0-18",
    "forwardPorts": [3000],
    "workspaceFolder": "/workspace/testfolder/someTestfolderInWorkspace",
    "workspaceMount": "dst=/workspace/testfolder,type=bind",
    "containerEnv": {
        "TESTVAR": "testValue"
    }
}

optionally you can also add source and readonly options to the workspaceMount property.

this should then put the workspace at the specified location and open the folder defined by workspaceFolder

Follow-ups

Breaking changes

• This PR introduces breaking changes and requires careful review. If yes, the breaking changes section in the changelog has been updated.

Attribution

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines