Improve Vertx Devfile and use official sample project

[sleshchenko]

Description

This issue is created as a consequence to a discussion here eclipse-che/che-devfile-registry#18 (comment)

Current Vertx Devfile is actually adapted Stack and sample that we used to use by in Devfile format.
There was a try to use official sample and all samples are in the same git repository and Devfile does not support keep directory yet.
It is needed to use a git submodule in our sample for something like the vert.x Simple REST microservice and:

• rework Devfile to use it;
• run Vertx application in vertx component but not in maven with fat jar;

Reproduction Steps

OS and version:

Diagnostics:

[che-bot]

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