Expose start/stop/clean commands as tasks

[stuartleeks]

This PR to the VS Code extension adds tasks that expose the start/stop/clean commands. This allows a user to automate the starting of Azurite services

Launch configurations in VS Code allow you to specify a task that should be run before launching the app/debugger. For example, tTo ensure that all services are started before launching a debug configuration, add "preLaunchTask": "azurite: start" to the configuration in launch.json (see the docs for more details).

Tasks can also be set to run when a folder opens (e.g. start the blob service when the folder opens):

{
  "tasks" : [
    {
      "type": "azurite",
      "action": "blob.start",
      "problemMatcher": [],
      "runOptions": {
        "runOn": "folderOpen"
      }
    }
  ]
}

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Thanks for contribution! Please go through following checklist before sending PR.

PR Branch Destination

• For Azurite V3, please send PR to main branch.
• For legacy Azurite V2, please send PR to legacy-dev branch.

Always Add Test Cases

Make sure test cases are added to cover the code change.

Add Change Log

Add change log for the code change in Upcoming Release section in ChangeLog.md.

Development Guideline

Please go to CONTRIBUTION.md for steps about setting up development environment and recommended Visual Studio Code extensions.