Add codestart data option in CLI and Maven plugin

Description

It would be nice extension codestart to have user customizable data. This is already possible in codestarts but not yet connected in the tooling.

It would behave like this:

quarkus create app -x=my-ext -d=my-ext-codestart.foo.bar=hello,my-ext-codestart.foo.hello=andy

The my-ext-codestart prefix is required by the codestart system to know the data is targeting this particular codestart data (and avoid conflicts)

The default value is in the codestart.yml:

name: my-ext-codestart
language:
  base:
    data:
      foo:
        bar: baz
        hello: world

FYI: I created this issue because @gsmet has a need for this.

[gsmet]

@arpitbhardwaj you can have a look if you can figure out where to do this.

[maxandersen]

so I now got to import the code and realize that -D already exist in more generic form. somehow I had in my head for codestarts we had separate dedicated command.

so all good - my only gripe is that it relies on command separated “blob” which limits what you can pass in but we can fix that if usecase arises by adding support for i.e. -QDkey=value or similar.