Add an option to control context auto startup

[lburgazzoli]

No description provided.

[lburgazzoli]

@gnodet

This PR is primary for discussion and need to be:

1. rebased on master
2. revised after we get quarkus-camel - Use MainSupport as base for running Camel #9 implemented

The goal here is to let the application control the camel context life-cycle as it seems there are some odd behavior when looking up beans from the ArC container if quarkus is not fully started.

What I have observed is that

RuntimeRegistry::findByType(Vertx.class) 

Which under the hoods leverage the BeanManager from ArC, returns null when the camel context starts before Quarkus is fully started but returns a proper Vertx instance when the same method is invoked after Quarkus is fully started.

This maybe need to be investigated more with @mkouba

[asf-ci]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/camel-quarkus-pr/139/

Build result: FAILURE

[...truncated 615.05 KB...] at java.lang.reflect.Method.invoke (Method.java:498) at hudson.maven.Maven3Builder.call (Maven3Builder.java:139) at hudson.maven.Maven3Builder.call (Maven3Builder.java:70) at hudson.remoting.UserRequest.perform (UserRequest.java:212) at hudson.remoting.UserRequest.perform (UserRequest.java:54) at hudson.remoting.Request$2.run (Request.java:369) at hudson.remoting.InterceptingExecutorService$1.call (InterceptingExecutorService.java:72) at java.util.concurrent.FutureTask.run (FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:624) at java.lang.Thread.run (Thread.java:748)[ERROR] [ERROR] Re-run Maven using the -X switch to enable full debug logging.[ERROR] [ERROR] For more information about the errors and possible solutions, please read the following articles:[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException[ERROR] [ERROR] After correcting the problems, you can resume the build with the command[ERROR] mvn -rf :camel-quarkus-integration-test-core-cdichannel stoppedAdding one-line test results to commit status...Setting status of 3b4744c to FAILURE with url https://builds.apache.org/job/camel-quarkus-pr/139/ and message: 'FAILURE 61 tests run, 2 skipped, 0 failed.'Using context: default