Non-external tests should not be performing requests to external
websites or services.
Add a mock to handle such requests:
- if the test is not tagged external
- and the request is not to localhost
- and the request is not to `file:` (it's possible to install a
FileAdapter in a session to resolve file URLs)
- raise a connection error (and log, both with some details of the
blocked request for debugging)
The mock is layered on the lowest possible level (`Session.send`), so
tests can either:
- reconfigure the mock to handle cases differently (the mock is
re-created on every test)
- layer their own mock at a higher level of the library
Eventually we might also built-in a routing / dispatch mechanism so
it's easier to declare external services you want to mock, somewhat
similar to what's available client-side.
Whitelist `file:` because e.g. zeep performs `file:` request, using a
bespoke adapter installed in its session.
Part-of: odoo/odoo#128497
Xavier Morel
4111f02fb3