Add basic auth ureqeusts and elementtree for xml.

Implement nextcloud directory listing.

ElementTree.py

@@ -55,6 +55,12 @@ class Element:
     def get(self, key, default=None):
         return self.attrib.get(key, default)
 
+    def find_first_by_tag(self, tag):
+        for child in self:
+            if child.tag == tag:
+                return child
+        return None
+
     def set(self, key, value):
         self.attrib[key] = value