[FZ Editor] snapping and moving splitters

[SeraphimaZykova]

Environment

Windows build number: 10.0.17763.973
PowerToys version: 0.14.1
PowerToy module for which you are reporting the bug (if applicable): FancyZones

Actual behavior

Splitters are placed incorrectly and they can't move throughout whole area

Screenshots

[crutkas]

xref #1032 for v2 editor

[SeraphimaZykova]

Fixed in #4095

[crutkas]

We just released 0.20 and this should be resolved there. Please try it out.