skip serializing (Synthetic)Events

[rhalff]

Revert old behavior of handling SyntheticEvents passed to the action handlers.

Fixes: #2590

[codecov]

Codecov Report

Merging #2626 into master will increase coverage by 0.04%.
The diff coverage is 88.88%.

@@            Coverage Diff             @@
##           master    #2626      +/-   ##
==========================================
+ Coverage   32.61%   32.65%   +0.04%     
==========================================
  Files         397      398       +1     
  Lines        8855     8868      +13     
  Branches      954      959       +5     
==========================================
+ Hits         2888     2896       +8     
+ Misses       5304     5298       -6     
- Partials      663      674      +11

Impacted Files	Coverage Δ
addons/actions/src/lib/util/index.js	100% <ø> (ø)	⬆️
addons/actions/src/preview.js	61.53% <100%> (-3.17%)	⬇️
addons/actions/src/lib/util/prepareArguments.js	57.14% <87.5%> (ø)
app/vue/src/server/config/babel.js	0% <0%> (-100%)	⬇️
app/react/src/server/utils.js	0% <0%> (-53.58%)	⬇️
addons/viewport/src/components/SelectViewport.js	15% <0%> (ø)	⬆️
addons/links/src/react/components/link.js	78.78% <0%> (ø)	⬆️
lib/ui/src/modules/ui/index.js	0% <0%> (ø)	⬆️
...-native/src/preview/components/OnDeviceUI/index.js	0% <0%> (ø)	⬆️
addons/info/src/components/PropTable.js	87.23% <0%> (ø)	⬆️
... and 54 more

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[tmeasday]

Works well, made some other comment on #2590