Add copyright headers

Dear @lga ,

We analysed the current code and found that your python source code files included a copyright header, in SPDX short version, while the rest of the files didn't have a header. We have produced a Merge Request to show mainly the type of headers we expect when IP Reviewing open source code.

We invite you to check each change because there are some cases in which the addition of the header can create issues, like in files which are input for another processes where a header may not be expected. Please have a look at them.

The use of the SPDX short version of copyright header is not incorrect. However we recommend the use of the full version as it allows the contributors to add his/her name and the type of contribution done. We have suggested in this merge request the full version copyright headers as those are the headers used in the rest of the CODECO repositories, in order to have consistency and homogeneity. Nevertheless, if IBM corporate guidelines don't allow the use of these headers, feel free not to approve the merge request, modify it, etc.

Feel free to be inspired and/or accept the whole Merge Request.

Thanks a lot

cc @mjahn0qp