* Return all viable matches between acceptable and requested encodings, ordered by highest preference first.
* TODO: sort equal q-values by server-preference rather than header order
* @param {string[]} acceptableEncodings e.g. ['br', 'gzip'] in order of server preference
* Return all viable matches between acceptable and requested encodings, ordered by highest preference first.
* TODO: sort equal q-values by server-preference rather than header order
* @param {string[]} acceptableEncodings e.g. ['br', 'gzip'] in order of server preference