CLIMATE-594 - Add 'origin' attribute to Dataset class
CLIMATE-594 - Add 'origin' attribute to Dataset class

- Add 'origin' attribute to the Dataset class for tracking where a
  dataset was loaded from. Future commits will update the data sources
  so that this attribute is set.

agoodm/climate,jarifibrahim/climate,riverma/climate,lewismc/climate,apache/climate,huikyole/climate,pwcberry/climate,agoodm/climate,MBoustani/climate,MJJoyce/climate,pwcberry/climate,agoodm/climate,huikyole/climate,riverma/climate,MBoustani/climate,apache/climate,lewismc/climate,Omkar20895/climate,agoodm/climate,apache/climate,pwcberry/climate,riverma/climate,riverma/climate,pwcberry/climate,Omkar20895/climate,Omkar20895/climate,lewismc/climate,MBoustani/climate,MBoustani/climate,Omkar20895/climate,jarifibrahim/climate,MJJoyce/climate,apache/climate,MJJoyce/climate,pwcberry/climate,huikyole/climate,huikyole/climate,apache/climate,jarifibrahim/climate,huikyole/climate,riverma/climate,MBoustani/climate,Omkar20895/climate,MJJoyce/climate,MJJoyce/climate,lewismc/climate,jarifibrahim/climate,lewismc/climate,agoodm/climate,jarifibrahim/climate