Cleanup and improve ApplicationFailure javadoc

[Spikhalskiy]

Cleanup and improve ApplicationFailure javadoc. Include how ApplicationFailure.newNonRetryableFailure() works together with ActivityOptions#retryOptions#setDoNotRetry and WorkflowImplementationOptions#setFailWorkflowExceptionTypes. Consider adding additional methods that allow the creation of non-retryable ApplicationFailure from an exception directly without wrapping to simplify handling on the receiving side.