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.

sat/plugins/plugin_xep_0103.py

@@ -46,7 +46,7 @@ class XEP_0103:
 
     def __init__(self, host):
         log.info(_("XEP-0103 (URL Address Information) plugin initialization"))
-        host.registerNamespace("url-data", NS_URL_DATA)
+        host.register_namespace("url-data", NS_URL_DATA)
 
     def get_url_data_elt(
         self,