scales ordering in precomputed info file

It looks like the order of the scale metadata has an effect on how neuroglancer renders multiscale data.

Somehow tensorstore seems to occasionally mis-order the entries in the `scales` field of `info` (possibly a side-effect of delayed evaluation?), which on its own should be OK, since the elements of `scales` can and should be sorted on their resolution, not on their index. But it seems that when this mis-ordering occurs, neuroglancer fails to render all the scales. e.g., when my lowest resolution scale is the first entry in `scales`, neuroglancer only detects that scale level and will not render higher resolution scales. A solution would be to ignore the order of the `scales` metadata element and instead generate the list of scales by parsing the `resolution` property of every element in `scales`.