improve our defaults for step parameters

[lhein]

For instance when adding a log processor it would be nice to already put in ${body} in the log message.

File: camel-component-default.service.ts

There are 2 types of defaults...one for the templates and another one for steps. Initially, we made them separately, but that's something to improve. Ideally, we should have defaults for steps only, and then the template should ask for those defaults instead. This way log component would be the same always.