Item geometry from raster data footprint

[pjhartzell]

Related Issue(s):

• Closes Add option to generate geometries from valid raster data footprint #94

Description:
Adds a raster_footprint option to create_item and create_item_from_cogs functions and to the CLI commands.

• Based on a subclass of the new stactools RasterFootprint class.
• If a raster footprint can not be generated, a warning is logged and the Item geometry defaults to the "tile geometry".

PR checklist:

• Code is formatted (run scripts/format).
• Code lints properly (run scripts/lint).
• Tests pass (run scripts/test).
• Documentation has been updated to reflect changes, if applicable.
• Example STAC Catalog has been updated to reflect changes, if applicable.
• Changes are added to the CHANGELOG.

[gadomski]

one that extracts the shapes in pixel coordinates and then applies the same manual reprojection and filtering to the pixel coordinates as currently done to produce the default "tile geometry".

Seems like this could be useful to push all the way to stactools, since we will at least have one other sinusoidal grid dataset (VIIRS) that will (presumably) want similar treatment?