replace typealiases with value classes

[LastExceed]

for actual type safety

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should dynamic endpoints be instantiable with both value class and underlying object ? if yes, then we'd need to overload the constructor which isnt possible because the JVM signature of the ctors would be identical, and the jvmname of a ctor cannot be altered via annotation. one way would be to implement operator fun invoke on the companion object but thats a huge smell. this problem probably wont exist anymore after #9 gets done though