v3.3.0 ASF/WMF Support

New Features / Fixes:

• Added support for ASF/WMF files
• Updated package.json to allow node.js >=12.16.1 🤦‍♂️
• Verified usage of 32-bit integers and "safe" javascript integers
  • Where "safe" integers are allowed, checks for "safe" were added
  • Where only 32-bit integers are allowed, checks for int/uint were added
• ByteVector class now accepts bigint or number for 64-bit integer operations
• Fixed bug in picture extension detection
• The codecs property of Properties returns a shallow copy of the codecs to prevent modification
  of the list of codecs

Probably Not Breaking Changes:

• IPicture and PictureType classes have moved to their own file ipicture.ts, index.ts exports
  have not changed
• Dropped usage of the BigInt.BigInteger from big-integer package and replaced with bigint
  type in TypeScript