Support multiple-point searches in queries

[Sherwin-14]

The current point function support's a single point only. Would be nice to have support for multiple points

[chuckwondo]

For reference:

• Search for collections by point(s)

• Search for granules by point(s). Note that the example shows only 1 point, but per finding granules by spatial:

  The parameters used for searching granules by spatial are the same as the spatial parameters used in collections searches. (See under "Find collections by Spatial" for more details.)

[chuckwondo]

Fixed by #73