tasks #7124 add event when comment is added/ modified

This is part of story #7030 Include approval table comments

Change-Id: I1c2bf8cdde06c605a2f73c74b8547dd209904e86
Merge commit 'refs/changes/94/2694/4' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #7124 add event when comment is added/ modified

Change-Id: Iea3e9906321fbcdb304b45c8eafb6a91a29ac03a
This is Tuleap 7.2.99.7

Change-Id: I4dec1750aea9533e307201c2a8f8a47cd93b2b4a