gst: fix awkward dest_format inout parameter in query utility functions

gst: fix awkward dest_format inout parameter in query utility functions

The idea was originally that if one passed &dest_fmt with
dest_fmt=GST_FORMAT_DEFAULT, then the code answering the query
could change dest_fmt to the actual default format used. However,
in more than half a decade of GStreamer 0.10 no piece of code in
GStreamer has ever used that feature, nor are there that many
users of this API that actually check whether the format returned
is the original format passed before using the values returned.
Also, it's just annoying-to-use API in its own right.

For all these reasons, make it so that the destination format is
passed directly and can't be changed by the element queried.