Checks to see if value is a valid SemVer object. It does a check into each field including prerelease and build.

Some invalid SemVer sentinels can still return true such as ANY and INVALID. An object which has the same value as a sentinel but isn't reference equal will still fail.

Objects which are valid SemVer objects but have extra fields are still considered SemVer objects and this will return true.

A type assertion is added to the value.