Inconsistency with paths

[sbanoeon]

Describe the bug
Some functions including the one below strips the base url, this results in http://host:port/version instead of http://host:port/some_path/version when using http://host:port/some_path as the base url for context broker.

FiLiP/filip/clients/ngsi_v2/cb.py

Line 152 in 41e7349

url = urljoin(self.base_url, "/version")

To Reproduce

Expected behavior
The resulting path in functions like get_version() in context broker is http://host:port/some_path/version.

Screenshots

Environment (please complete the following information):

Additional context

[github-actions]

Branch 251-Inconsistency-with-paths created!