Add some sugar for additional sources

[nicolaferraro]

When I need to add a customizer (i.e. an additional source that adds a different behavior) to an integration I run something like:

kamel run Basic.java customizers/OpentracingCustomizer.java --name basic --another-arg --a-second-arg --many-other-args --save

The problem is that after I --save the arguments passed to the command, if I want to run the integration again, I still need to pass the customizer and the integration name:

# After saving the arguments
kamel run Basic.java
# Does not work, because the customizer is a positional argument, not a named one 

This works instead:

kamel run Basic.java customizers/OpentracingCustomizer.java --name basic

But the purpose of --save is to let you write as less arguments as possible, so it's not nice.

I wonder if we can add a --source argument.

With that option, one would run the integration the first time with:

kamel run Basic.java --source customizers/OpentracingCustomizer.java --another-arg --a-second-arg --many-other-args --save

And the second time, just:

kamel run Basic.java

The customizer will be saved in the configuration.

[nicolaferraro]

That also allow e.g. to create customizers for all integrations (e.g. an OpenTracingCustomizer) and reuse it automatically after saving it in the global config.