Remove unnecessary language extensions

src/Algorithm.hs

src/Data/BlockQueue.hs

src/Data/Functors.hs

src/Data/MorphismEncoding.hs

src/Data/OpenUnion.hs

src/Data/RefinementInterface.hs

src/Data/Sort.hs

src/Parser.hs

src/Text/Parser/Lexer.hs

tests/Data/RefinablePartitionSpec.hs

tests/DocTests.hs