Bring together all requests modification into one function
Bring together all requests modification into one function

Also, we now call `sendHttpRequestMetric` after request modifications so
we are sure that the request will be the same here and when the
LOADING_COMPLETED will be raised.

Signed-off-by: Jean-Baptiste Louazel <db9a98fea6dbd557aabc650ff3d24e4c2be7ce0f@gmail.com>

streamroot/dashjs-p2p-wrapper,streamroot/dashjs-p2p-wrapper,streamroot/dashjs-p2p-wrapper