Fix Equality To Be Consistent With Compare In Version

[isomarcte]

This commit fixes the def equals method to be consistent with compare in Version. The reason for the inconsistency was that data-class was generating an equals method based off the repr (e.g. this.repr == that.repr), however compare is encoded to determine logical equality of a binary API with respect to SemVer (sort of). That is to say, compare compares two values by padding them to equal numeric length and then dropping the metadata value.

Unfortunately, we can not simply override the equals method and use the @data annotation (attempting to do so causes a compilation error). Thus this commit re-implements the methods from @data, but only for Version. Data types which do not implement Ordered do not need this special case treatment.

The implementation of compare likely bares some further discussion. It creates a situation where the hashCode and equality are unexpected for users cases other than comparing binary APIs.

For example, if I want to create a Set of Version values, this is likely unexpected behavior.

scala> Set(Version("1.0.0"), Version("1.0"), Version("1.0.0+SOME_META"))
val res0: scala.collection.immutable.Set[coursier.version.Version] = Set(Version(1.0.0))

Though there is no other way to implement equals and hashCode such that it is consistent with the current implementation of compare, however changing compare may likely have some unintended consequences as well.

[isomarcte]

This PR is a draft until #13 is resolved.