Fix picking media not updating thumbnails

[emptynick]

When a file was double-click to pick it, the UI didn't refresh.
This fixes it.
Also fixed a problem where images weren't displayed when the extension was uppercase (ex. myfile.JPG)

Fixes #4969

[codecov]

Codecov Report

Merging #4970 into 1.4 will not change coverage.
The diff coverage is 75.00%.

@@            Coverage Diff            @@
##                1.4    #4970   +/-   ##
=========================================
  Coverage     62.96%   62.96%           
  Complexity     1372     1372           
=========================================
  Files           194      194           
  Lines          4007     4007           
=========================================
  Hits           2523     2523           
  Misses         1484     1484           

Impacted Files	Coverage Δ	Complexity Δ
src/Traits/Translatable.php	37.65% <75.00%> (ø)	61.00 <0.00> (ø)

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[MrCrayon]

Works 👍
This is the reason I thought it was buggy but I never looked into it properly.