Function isBlob

Checks if a value is a Blob or Blob-like object.

Works across environments:

• Browser native Blob
• Node.js Blob (v15.7.0+)
• Node.js Buffer (detected separately, not a Blob)
• Polyfills (e.g., fetch-blob, formdata-node)
• Custom implementations

Detection strategy:

1. Native instanceof check (fastest path)
2. Duck typing with required properties + at least one Blob-specific method
3. Constructor name fallback for edge cases (polyfills, cross-realm)