Rewrite in TypeScript

[isaacs]

This is a big one, please read carefully before upgrading from
prior versions, especially if you extend Minipass in a subclass.

Breaking Changes

• Rewritten in TypeScript as hybrid esm/cjs build, so a lot of
  types changed in subtle ways, and several behaviors got
  stricter.
• Minipass now inherits from EventEmitter rather than Stream.
  Nothing from the Stream class was ever used by Minipass, but
  it inherited from Stream to pass checks in some stream
  libraries that checked instanceof Stream. Unfortunately, the
  type difference in the pipe() method signature made it
  challenging to continue doing in TypeScript.
• It is no longer possible to change the type of data emitted
  after a Minipass stream is instantiated, as this would thwart
  TypeScript's static checks. As a consequence:
  • The setEncoding method and the encoding setter are
    deprecated. Encoding may only be set in the constructor
    options object.
  • objectMode is no longer inferred by writing something other
    than a string or Buffer. It may only be set in the
    constructor options object.
• If all existing data consumers are removed, via
  stream.unpipe(dest), stream.removeListener('data', handler),
  stream.removeAllListeners('data'), and/or
  stream.removeAllListeners(), then the data will stop flowing.
  Note that it is still possible to explicitly discard a stream's
  data by calling stream.resume() in the absence of any
  consumers.

Features and Fixes

• Removed a very subtle performance issue that made objectMode
  Minipass streams slower in some cases than node core streams.
  Minipass is now faster than node core streams for all data
  types.
• The array returned by stream.collect() for objectMode streams
  will have a dataLength property equal to 0, rather than
  undefined.
• isStream is moved from a static member on the Minipass class
  to a named export.
• isWritable() and isReadable() methods added.