INTEG-303: Revert "INTEG-292: [integ-wiki] HTML encoding of wiki page's content when like a wiki activity"

This reverts commit 30c61191bc0b88854812030f89fea4113ec066b9.
INTEG-289: [Security] Detail of question in FORUM has XSS vulnerability

Fix description:
* Revert the previous commit (c0b9f0437) which cleans the whole scripts inside activity content
* Use activity body (XSS vulnerability has been handled) for activity content.
Merge commit 'bf1d890c9b15273ce22b199740adc3b40ec672cc' into HEAD