Update 5.9.3-SNAPSHOT to 5.9.4-SNAPSHOT
NXP-14281: fix export of dates when serializing search document model for content views + add non-regression test
NXP-14281: use UTC timezone when formatting date for json export
NXP-14168: Add the group widget when inviting a user.
NXP-11406: Remove the previous version of tinyMCE.
NXP-11406: Add the version 4.0.21 of TinyMCE.
NXP-11406: Increase the default size of the textarea to fit with the new ui of tinyMCE.
NXP-11406: Configure the new version of tinyMCE.
NXP-11406: Add the Nuxeo plugins.