Creation extension command needs artifactIdPrefix

[aureamunoz]

The parameters that will be constant for all the extensions are configured in extensions/pom.xml. This config introduces a build dependency on the maven plugin which leads to an ordering that prevents the tooling to include the generated JSON platform descriptor so has been commented.
Thus, the command to add a new extension to the Quarkus source tree needs to pass also the artifactIdPrefix otherwise an error is raised.
Here is the stacktrace:

mvn io.quarkus:quarkus-maven-plugin:0.27.0:create-extension -N \
                                                            -Dquarkus.artifactIdBase=my-ext \
                                                            -Dquarkus.nameBase="My Extension"
[INFO] Scanning for projects...
[INFO] 
[INFO] ---------------------< io.quarkus:quarkus-parent >----------------------
[INFO] Building Quarkus - Parent pom 999-SNAPSHOT
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] 
[INFO] --- quarkus-maven-plugin:0.27.0:create-extension (default-cli) @ quarkus-parent ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  1.770 s
[INFO] Finished at: 2019-10-31T09:02:33+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal io.quarkus:quarkus-maven-plugin:0.27.0:create-extension (default-cli) on project quarkus-parent: Either artifactId or both artifactIdPrefix and artifactIdBase must be specified; found: artifactId=[null], artifactIdPrefix=[null], artifactIdBase[my-ext] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

Could you please take a look @geoand or forward this PR to someone else?

[geoand]

Seems reasonable to me but maybe @maxandersen has some more input?

[maxandersen]

not fully following this one - we shouldn't require users to add prefix. We should fix what is breaking it instead.

[geoand]

Asking because we haven't followed the evolution of the devtools. I personally didn't even know there was such a command :)

[aureamunoz]

Maybe this helps to understand --> the config setting the commons parameters has been commented so now the artifactIdPrefix is needed.

[geoand]

@maxandersen if what @aureamunoz mentions checks out, I think we should at least update the docs for now

[maxandersen]

+1

@aloubyansky wdyt ?

[aloubyansky]

+1

[geoand]

Let's add this for the time being and revisit post 1.0.

Thanks @aureamunoz for spotting and this and updating the docs!