RteOpenData base voltage format has changed

[mathbagu]

• Do you want to request a feature or report a bug?
  Bug

• What is the current behavior?
  There is an AssertionError(63kv) thrown when we try to show the map. There is also an error for "INFERIEUR A 45 KV".
  We should be able to parse old and new versions of the OpenRTE data files.

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem
  Download the last versions of RTE OpenData files (lignes-aeriennes-rte.csv, lignes-souterraines-rte.csv and postes-electriques-rte.csv) from https://opendata.reseaux-energies.fr
  Put these files in ~/.itools and show the map in GSE.

• What is the expected behavior?
  The exception should not be thrown.

• What is the motivation / use case for changing the behavior?

• Please tell us about your environment:

  • PowSyBl Version: 2.4.1
  • OS Version: ...

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, spectrum, etc)

(if a question doesn't apply, you can delete it)