fix: add helpful suggestions to generator error messages (fixes #1728)

[gavin913427-hash]

What does this PR do?

Adds helpful suggestions to generator error messages when asyncapi generate fromTemplate fails (fixes #1728)

Changes

Enhanced error handling in src/apps/cli/commands/generate/fromTemplate.ts to detect common failure patterns and suggest actionable fixes:

• Template not found (ENOENT/not found): Suggests installing the template first
• Invalid document (parse/syntax errors): Suggests validating the document with asyncapi validate
• 404 errors: Suggests checking the template name on npm

Before

Error: ENOENT: no such file or directory

After

Error: ENOENT: no such file or directory

Possible causes:
  - The template may not be installed. Try installing it first with: npm install <template-name>

Related issue(s)

Fixes #1728

Checklist

• Added error pattern detection for common failures
• Added actionable suggestions
• Preserved original error message when no patterns match
• Added changeset

[changeset-bot]

🦋 Changeset detected

Latest commit: 091c168

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@asyncapi/cli	Patch

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[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud