breaking(Popup): switch to Popper.js

[layershifter]

BREAKING CHANGES

This PR removes our positioning logic and uses react-popper instead.

Removal of keepInViewport

This prop was removed and will be introduced again later.

Removal of horizontalOffset & verticalOffset, use offset now

Popper.js uses more flexible offset, please follow their docs.

<Popup
-  horizontalOffset={50}
-  verticalOffset={50}
+ offset='50, 50'
/>

(!) Offset in Popper works differently than horizontalOffset & verticalOffset:

For length is intended the main axis relative to the placement of the popper.
This means that if the placement is top or bottom, the length will be the width. In case of left or right, it will be the height.

Changes in behavior

Popup changes its position more accurate now.

Before

After

---

Fixes #1126.

Before

After

Fixes #3226

After

Fixes #3505

Fixes #3478

Before

After

[codecov-io]

Codecov Report

Merging #3532 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #3532      +/-   ##
==========================================
- Coverage   99.82%   99.81%   -0.01%     
==========================================
  Files         172      174       +2     
  Lines        2795     2725      -70     
==========================================
- Hits         2790     2720      -70     
  Misses          5        5

Impacted Files	Coverage Δ
src/modules/Popup/Popup.js	98.24% <100%> (-1.02%)	⬇️
src/modules/Popup/lib/createReferenceProxy.js	100% <100%> (ø)
src/modules/Popup/lib/positions.js	100% <100%> (ø)

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[semireg]

Is there a guide anywhere that shows how to upgrade from something like 0.84.0 with regards to Popper? The CHANGELOG says "Breaking" but offers no hints on how to fix the expected breaks. Thank you for the hard work, everyone!

[HardenIan]

Is there a guide anywhere that shows how to upgrade from something like 0.84.0 with regards to Popper? The CHANGELOG says "Breaking" but offers no hints on how to fix the expected breaks. Thank you for the hard work, everyone!

I have a feeling the "Breaking" change is the offset props being removed and the new combined offset being added.