[CLI] Update generationStatus handling in ArtifactGenerator

[virkt25]

Description / Steps to reproduce / Feature proposal

As per the comment here: #1487 (comment)

Ideally, I think we should generationStatus file by file now instead of a global flag. For example,
models/model-1.ts (success)
models/model-2.ts (skipped)

Current generationStatus check:

 let generationStatus = true;
    // Check all files being generated to ensure they succeeded
    Object.entries(this.conflicter.generationStatus).forEach(([key, val]) => {
      if (val === 'skip' || val === 'identical') generationStatus = false;
    });

Acceptance Criteria

• Move generationStatus check in ArtifactGenerator out of end -- but after scaffold to handle multiple files.
• Update the generationStatus to support handling of multiple files
• Move the call to _updateIndexFiles from end to outside of end (before it but after generationStatus check (or maybe part of the same function))

Helpful Links

• http://yeoman.io/authoring/running-context.html

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[stale]

This issue has been closed due to continued inactivity. Thank you for your understanding. If you believe this to be in error, please contact one of the code owners, listed in the CODEOWNERS file at the top-level of this repository.