Update tasks.json for publishing generation output

[zengin]

Related #513

• Reuse PowerShell scripts used in generation pipelines to copy from generation output folder to the corresponding SDK project.
  • Current launch.json for Java points to the SDK project directly for generation output. This could work for additive scenarios, but if a type is removed, it won't be reflected. Reusing generation scripts would give us that "cleaning the old models" step for free.
• Consider integrating these tasks into launch JSON as post debug tasks. See comment: https://github.com/microsoftgraph/MSGraph-SDK-Code-Generator/pull/515#discussion_r613326319

AB#8979