Rework the scripts as maven plugin

[claudio4j]

Rework the generator.go and validator.go from the scripts directory as kamelet maven plugin to facilitate maintenance and consistency in the project regarding the primary programming language as java.

[oscerd]

For the validation there is already a validate-maven-plugin: the aim is to check if the Camel catalog shows the parameters we use in the Kamelet templates. If not, it will fail.

[claudio4j]

The intention is to move the go code to the existing maven plugin and create a new generator mojo. Because today, we have to run the maven plugin and the go scripts when there are changes in the kamelets.