update mathjax to 2.6 (TNL-4104) and (TNL-4094)

update mathjax class names to support common html, html-css, and svg

common/test/acceptance/pages/lms/discussion.py

@@ -126,7 +126,7 @@ class DiscussionThreadPage(PageObject, DiscussionPageMixin):
     def verify_mathjax_rendered(self):
         """ Checks that MathJax css class is present """
         self.wait_for(
-            lambda: self._is_element_visible(".MathJax"),
+            lambda: self._is_element_visible(".MathJax_CHTML"),
             description="MathJax Preview is rendered"
         )
 

common/test/acceptance/pages/lms/problem.py

@@ -49,7 +49,7 @@ class ProblemPage(PageObject):
         """
         def mathjax_present():
             """ Returns True if MathJax css is present in the problem body """
-            mathjax_container = self.q(css="div.problem p .MathJax .math")
+            mathjax_container = self.q(css="div.problem p .MathJax_CHTML")
             return mathjax_container.visible and mathjax_container.present
 
         self.wait_for(
@@ -63,7 +63,7 @@ class ProblemPage(PageObject):
         """
         def mathjax_present():
             """ Returns True if MathJax css is present in the problem body """
-            mathjax_container = self.q(css="div.problem div.problem-hint .MathJax .math")
+            mathjax_container = self.q(css="div.problem div.problem-hint .MathJax_CHTML")
             return mathjax_container.visible and mathjax_container.present
 
         self.wait_for(

common/test/acceptance/pages/lms/tab_nav.py

@@ -40,7 +40,7 @@ class TabNavPage(PageObject):
         """
         Check that MathJax has rendered in tab content
         """
-        mathjax_container = self.q(css=".static_tab_wrapper .MathJax .math")
+        mathjax_container = self.q(css=".static_tab_wrapper .MathJax_CHTML")
         EmptyPromise(
             lambda: mathjax_container.present and mathjax_container.visible,
             "MathJax is not visible"