style(Message): update typings and remove propTypes

[layershifter]

This PR is part of work for removing propTypes in production bundle (#524, #731).
Also, cleanups and updates typings for #1072.

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Also, it converts Message to statefull components and update onDismiss behavior.

[codecov-io]

Codecov Report

Merging #1254 into master will increase coverage by -0.01%.

@@            Coverage Diff             @@
##           master    #1254      +/-   ##
==========================================
- Coverage    95.9%   95.89%   -0.01%     
==========================================
  Files         881      880       -1     
  Lines        4904     4899       -5     
==========================================
- Hits         4703     4698       -5     
  Misses        201      201

Impacted Files	Coverage Δ
src/collections/Message/MessageContent.js	100% <ø> (ø)	✅
src/collections/Message/MessageHeader.js	100% <100%> (ø)	✅
src/collections/Message/Message.js	100% <100%> (ø)	✅
src/collections/Message/MessageItem.js	100% <100%> (ø)	✅
src/collections/Message/MessageList.js	100% <100%> (ø)	✅
src/views/Statistic/Statistic.js	100% <ø> (ø)	✅
src/views/Statistic/StatisticGroup.js	100% <ø> (ø)	✅
src/elements/Button/ButtonGroup.js	100% <ø> (ø)	✅
src/collections/Grid/GridRow.js	100% <ø> (ø)	✅
src/views/Statistic/StatisticLabel.js	100% <ø> (ø)	✅
... and 4 more

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[levithomason]

Perfect, thanks. I made one trivial update to the MessageItem description (added "list").

[levithomason]

Released in semantic-ui-react@0.64.5.