refactor gallery and maybe others for wordings of location and path

[ReimarBauer]

We have a mismatch of namings in the gallery. STATIC_LOCATION is used as path while on web sites that is meant as web location.

We should use path for pathes and location for web urls

• locations use https://werkzeug.palletsprojects.com/en/2.0.x/urls/
• path use https://docs.pyfilesystem.org/en/latest/reference/path.html or os.path