Switching class loader in AnyCodec does not work for Mongo

[PetrosPapapa]

In Kafka, AnyCodec requires an explicit class loader to be provided, hence this trick:

pew/pew/src/main/scala/com/workflowfm/pew/mongodb/bson/AnyCodec.scala

Lines 23 to 26 in 4a5bfae

	// Jev, unset the `ClassLoader` to ensure the default is used.
	def classForName(name: String): Class[_] = ClassLoaderUtil.withClassLoader(null) {
	Class.forName(name)
	}

See also:

• https://stackoverflow.com/questions/37363119/kafka-producer-org-apache-kafka-common-serialization-stringserializer-could-no
• https://stackoverflow.com/questions/57574901/kafka-java-client-classloader-doesnt-find-sasl-scram-login-class

This requires this switch using setContextClassLoader:

pew/pew/src/main/scala/com/workflowfm/pew/util/ClassLoaderUtil.scala

Lines 14 to 20 in 4a5bfae

	val pushedClassLoader = Thread.currentThread().getContextClassLoader
	try {
	Thread.currentThread().setContextClassLoader(tmpClassLoader)
	fnWrapped
	} finally {
	Thread.currentThread().setContextClassLoader(pushedClassLoader)
	}

This fails in pew-mongo because everything runs on the default ForkJoinPool which produces InnocuousThreads which do not allow you to setContextClassLoader leading to a security exception.

We want an easy way to bypass this loader switch, perhaps as simpke as a flag in AnyCodec and the codec provider.

Perhaps later on after #55 is implemented we will have a more elegant solution available.