[CAMEL-16907] camel-jt400 program call usability and doc improvements

[ThePrez]

Added usability improvements to the program call support as documented in the referenced JIRA issue.

Also, snuck in some doc improvements:

• Stopped referring to it as "remote program call" as we have a lot of people running Camel on IBM i now
• Removed the 'type' path parameter (it's not required since the type is inferred from the path)
• added a more practical program call example

[ThePrez]

Converting to draft to add doc to more explicitly address concerns in this JIRA ticket

[ThePrez]

I pushed a couple more commits. e2d6043 stops handling input parameters based on whether it's in binary mode. In the old design, binary mode required a byte[] and text mode required a String, now it is tolerant enough to accept either.

e54d709 clarifies the parameter handling in the documentation to address the concern in CAMEL-16899