The following is a full list of Buffer APIs used by the driver:

• .isBuffer
  • Does not exist; but we'll either want to remove usages of this from the driver (we'll need to evaluate on a case-by-case basis) or use `isUint8Array`, which exists in BSON.  Maybe it makes sense to export isUint8Array from BSON too.
• .concat
  • We'll need to add this to ByteUtils.
• .from
  • The driver uses Buffer.from to convert the following to buffers:
    • utf8 strings
    • number arrays
    • buffers
    • base64 strings
  • Byte utils supports converting base64 strings and number arrays to Uint8Arrays already.  converting buffers to buffers can be done using `isUint8Array` and conditionally converting the string argument to a buffer if needed.  We will need to add conversion of utf8 strings -> buffers to byte utils.
• .equals
  • exists in ByteUtils.
• .compare
  • We will need to implement .compare() for Uint8Arrays.  Alternatively, this is only used for ObjectIds in the driver - we could hard-code this logic into a new method, ObjectId.compare().
• .toBase64
  • exists in ByteUtils
• .allocUnsafe
  • exists in ByteUtils
• .alloc
  • exists in ByteUtils
• .readInt32LE
  • exists in NumberUtils

Acceptance Criteria:

• Implement any missing APIs from the list above in BSON.
• Export BSON ByteUtils from the library.