Open validator as GitHub action

[adineh]

Current State

The basic pipeline has been stablished.

How to test

git clone https://github.com/GAIA-X4PLC-AAD/OpenValidator.git
git checkout OpenValidator_as_github_action
change the contents of the "data/inputs/sampleODR" file and save it
git add .
git commit .....
git push
open page https://github.com/GAIA-X4PLC-AAD/OpenValidator/actions to see the new action and the results.
When the file is valid, OpenValidator will exit with the code "0" and the action will be Green (success), otherwise if the file is not valid, the OpenValidator will exit with the code "1" and the action will be red.