[Kotlin-kmp] Use built-in enum class

[DadiBit]

Using the built-in enum class kotlin's enum implementation makes the final code easier to read, cleaner, more standard.

To stay backward compatible, I had to add a "name" method and a "names" property. Same story goes for the operator invoke, which replaces the old class constructor.

Notes:

• On line 404 I also added a ';' between the actual enum entries (split by ',') and the companion object.
• Could removing the JvmInline annotation be an issue? I'm "against" using it in the first place, since it's KMP, not Kotlin on JVM.
• Each entry now holds a sourceName, which can be eitehr retrieved with someEntry.sourceName or someClass.name(someEntry)

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[paulovap]

Hi @DadiBit, the main reason for not using native enum is the performance penalty of using it as compared to primitives (or inline classes). The library focus on performance over ergonomics, so we are in favor of improving the ease of use only if the performance trade of is worth it.