Land sea mask generation

[lee1043]

• Add the land sea mask generation capability using regionmask
• Replace CDAT's landseamask generation to the new function
  • mean climate
  • precipitation variability

[lee1043]

Sanity check:

• demo 1b notebook results are consistent -- mostly identical numbers
• demo 7 notebook results are consistent -- statistics differ from 3rd from decimal point

[acordonez]

I'll test this out in the extremes metrics branch

[acordonez]

@lee1043 This looks fine to me:

[acordonez]

@lee1043 This looks fine to me:

I actually did not implement the new mask correctly and I believe this is using the pcmdi_utils version...still working on testing the extremes

[lee1043]

@acordonez Thank you for checking. Please let me know when you done testing this with extreme branch. If merging this PR into main would better help your testing of extreme branch, I can also do that.

[acordonez]

@lee1043 This time I should be using the new land/sea mask, I pulled all the other code out of my branch: