Add PairwiseDocNewUIESA Page

[GuoNa1]

Add PairwiseDocNewUIESA Page

[snukky]

Thanks for this PR! It looks good, but I have a few small suggestions before we merge:

1. We can drop "-newui" or "NewUI" from the class/method/URL names for simplicity.
2. I would like you to try introducing the new model class through inheritance instead of copy-pasting the entire class. I believe it's doable, but please feel free to object.
3. We should add a new regression test in RegressionTests/tests/examples to make sure we don't break it in future. It may be helpful to do it before addressing the points above.
4. Can you also briefly check if none of the PRs pulled today to the develop branch didn't change any logic in ESA tasks, which you use here?

I will then take another look. Thank you :)

[snukky]

Thank you very much for this PR! Everything seems to look good. Can you only summarize changes in the model file here (see one of the comments)? I think it may be useful for future reference.
I'd like to merge it after we finish WMT campaigns, which should be very soon.