0.7.0: Cats effect 3, Scala 3 support, Maven central

• Migrated to cats-effect 3.
• Support Scala 3.
• Rewrote Propagation.
• Changed organization from com.github.fehu to io.github.fehu.
• Renamed artifacts (opentracing-scala- core / fs2 / akka ...)
• Publish to sonatype.
• Release pipeline.

See also #7