Ensure satellite img dictionarys have consistent metadata

[jhkennedy]

sometimes they come as string and sometimes as numeric values, so @mliukis has them all listed when grouping in composites:

LANDSAT89 = MSTuple('L89', ['8.', '9.', '8.0', '9.0', 8.0, 9.0], 'L8_L9')
SENTINEL1 = MSTuple(‘S1’, ['1A', '1B’], ‘S1A_S1B’)
SENTINEL2 = MSTuple(‘S2’, ['2A', '2B'], ‘S2A_S2B’)