Update to QA pixel for Landsat collection 2

[andrewcharles]

Hi, just letting you know that I updated the QA bitmask for Landsat collection 2 on GEE. It's in a fork of the repo at:
andrewcharles@cb4b776

Given you're refactoring I figured you might already be onto these sort of changes but I'm happy to make a pull request if the team think this is a useful change.

[12rambau]

Hi @andrewcharles, if you look at the current state of v1 (I need to make a pre-release but didn't find the time yet) you will see that I decided to rely on ee_extra for all the pre-processing steps of the Image/ImageCollection. Specifically cloud mask is performed here:

https://github.com/gee-community/gee_tools/blob/6337ae98dfa77a743508513b88b20244c3a3bca2/geetools/Image/__init__.py#L1135

If what you're adding is already supported in ee_extra then we are good to go, if not I think you should go directly to their repository and discuss with them:

https://github.com/r-earthengine/ee_extra

[andrewcharles]

I might have time to take a look the week after next. The pull request is sitting there, if it turns out it replicates what's already supported by ee_extra I'll withdraw it. Cheers.