Refactoring isGIF() as a utility function

[rishabhshuklax]

Fixes #1501

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[rishabhshuklax]

@keshav234156 Do you know why UI tests are failing?
@harshkhandeparkar ?

[codecov]

Codecov Report

Merging #1511 into main will increase coverage by 1.4%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             main    #1511     +/-   ##
=========================================
+ Coverage   65.56%   66.97%   +1.4%     
=========================================
  Files         129      129             
  Lines        2628     2628             
  Branches      426      426             
=========================================
+ Hits         1723     1760     +37     
+ Misses        905      868     -37

Impacted Files	Coverage Δ
src/util/ParseInputCoordinates.js	92.85% <0%> (-7.15%)	⬇️
src/modules/Channel/Module.js	93.75% <0%> (+6.25%)	⬆️
src/modules/ReplaceColor/ReplaceColor.js	100% <0%> (+7.4%)	⬆️
src/modules/ColorTemperature/Module.js	94.73% <0%> (+10.52%)	⬆️
src/util/getStep.js	25% <0%> (+14.28%)	⬆️
src/modules/Dither/Dither.js	76.74% <0%> (+18.6%)	⬆️
src/modules/FlipImage/flipImage.js	100% <0%> (+20%)	⬆️
src/modules/NoiseReduction/NoiseReduction.js	100% <0%> (+34.78%)	⬆️

[rishabhshuklax]

@publiclab/is-reviewers please review this

[jywarren]

Hmm, this is showing up oddly in my interface. Maybe GitHub UI changed? Can you rebase this, it's not offering me an easy button to do so myself!

Thank you! this is great.

[rishabhshuklax]

@jywarren Done!

[jywarren]

Great! Thank you!!!