HLS: Add support for QUERYPARAM variable type in #EXT-X-DEFINE

[duggaraju]

Have you read the FAQ and checked for duplicate open issues?
YEs

Is your feature request related to a problem? Please describe.

This is just the gap with the latest HLS spec.

Describe the solution you'd like

Per HLS spec: https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis#section-4.4.2.3
QUERYPARAM

  The value is a quoted-string which specifies the Variable Name and
  indicates that its value is the value associated with the query
  parameter of the same name in the URI of the Playlist.  The valid
  character set for the quoted-string is the same as for the NAME
  attribute.  The value associated with the query parameter MUST be
  percent-decoded before performing the variable replacement.  The
  decoded value MUST NOT contain any of the characters disallowed in
  quoted-strings.

  If the QUERYPARAM attribute value does not match any query
  parameter in the URI or the matching parameter has no associated
  value, the parser MUST fail to parse the Playlist.  If more than
  one parameter matches, any of the associated values MAY be used.

  If the URI is redirected, the client MUST look for the query
  parameter in the 30x response URI.

Describe alternatives you've considered

Alternative would be writing a network plugin which will not work with native iOS playback.

Additional context

Requring a query string with token for authentication when playing HLS . However for native playback (iOS) you would need to update manifest and either use a variable or rewrite the URLs. With the queryparam approach you can substitute the variable outside with a query parameter.

[avelad]

@duggaraju are you interested in send a PR for it?

[avelad]

I'll work on this in a few days