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_0422.py

@@ -60,12 +60,12 @@ class XEP_0422(object):
     def __init__(self, host):
         log.info(_("XEP-0422 (Message Fastening) plugin initialization"))
         self.host = host
-        host.registerNamespace("fasten", NS_FASTEN)
+        host.register_namespace("fasten", NS_FASTEN)
 
-    def getHandler(self, __):
+    def get_handler(self, __):
         return XEP_0422_handler()
 
-    def applyToElt(
+    def apply_to_elt(
         self,
         message_elt: domish.Element,
         origin_id: str,
@@ -93,9 +93,9 @@ class XEP_0422(object):
         apply_to_elt = message_elt.addElement((NS_FASTEN, "apply-to"))
         apply_to_elt["id"] = origin_id
         if clear is not None:
-            apply_to_elt["clear"] = C.boolConst(clear)
+            apply_to_elt["clear"] = C.bool_const(clear)
         if shell is not None:
-            apply_to_elt["shell"] = C.boolConst(shell)
+            apply_to_elt["shell"] = C.bool_const(shell)
         if children is not None:
             for child in children:
                 apply_to_elt.addChild(child)
@@ -111,7 +111,7 @@ class XEP_0422(object):
         return apply_to_elt
 
     @async_lru(maxsize=5)
-    async def getFastenedElts(
+    async def get_fastened_elts(
         self,
         client: SatXMPPEntity,
         message_elt: domish.Element