Securely implement UUIDGen for Scala.js

[armanbilge]

This PR relates to CVE-2022-28355 aka GHSA-j2f9-w8wh-9ww4 regarding the insecure implementation of java.util.UUID.randomUUID() in Scala.js.

The fix implemented by Scala.js was to re-implement java.util.UUID.randomUUID() in terms of java.security.SecureRandom, and then make two SecureRandom artifacts available:

• https://github.com/scala-js/scala-js-java-securerandom
• https://github.com/scala-js/scala-js-fake-insecure-java-securerandom

Although depending on the fake artifact is strongly discouraged, it's still out there. After discussing with @cquiroz, given the lack of failure mode and non-determinism should both artifacts somehow end up on the classpath, it seems the safest thing to do is avoid using either of these in Cats Effect and instead rely on our own secure implementation.

This is reminiscent of the situation with the two weak reference libs, in which we decided to shade the "true" implementation within CE in #2673 (comment).

This PR does two things:

1. Replace the JavaSecureRandom from Implement Random#javaSecuritySecureRandom on Scala.js #2906 with the implementation from https://github.com/scala-js/scala-js-java-securerandom
2. Implement UUIDGen on Scala.js by inlining the changes from Fix #4657: Implement UUID.randomUUID() using java.security.SecureRandom. scala-js/scala-js#4659 using our internal JavaSecureRandom