massive refactoring to switch from camelCase to snake_case:

historically, Libervia (SàT before) was using camelCase as allowed by PEP8 when using a
pre-PEP8 code, to use the same coding style as in Twisted.

However, snake_case is more readable and it's better to follow PEP8 best practices, so it
has been decided to move on full snake_case. Because Libervia has a huge codebase, this
ended with a ugly mix of camelCase and snake_case.

To fix that, this patch does a big refactoring by renaming every function and method
(including bridge) that are not coming from Twisted or Wokkel, to use fully snake_case.

This is a massive change, and may result in some bugs.

tests/e2e/libervia-cli/test_libervia-cli.py

@@ -219,7 +219,7 @@ class TestLiberviaCliBlog:
         assert metadata['node'] == self.MICROBLOG_NS
         assert metadata['rsm'].keys() <= {"first", "last", "index", "count"}
         item_id = item['id']
-        expected_uri = uri.buildXMPPUri(
+        expected_uri = uri.build_xmpp_uri(
             'pubsub', subtype="microblog", path="account1@server1.test",
             node=self.MICROBLOG_NS, item=item_id
         )