LPS-48193 add a new `VIEW_KB_FEEDBACK` permission

Regular users shouldn't be able to see feedback.
LPS-48193 add skeleton page structure
LPS-48193 add status to feedback

Feedback can be in 3 different states: pending, in progress, and resolved.

We are not using the workflow to manage feedback state because we want
users to be able to manage it without forcing them to install Kaleo.
LPS-48193 add queries to get comments by state
LPS-48193 expose queries in local and non local services
LPS-48193 add listing for each feedback state
LPS-48193 add status transitions
LPS-48193 add feedback notification templates
LPS-48193 send notification when feedback is updated

When feedback is added or changes state, send a notification to the user
that created the feedback.
LPS-48193 add feedback configuration view

Allow admins to customize the email templates used for notifications.
LPS-48193 add some space between action buttons and feeback body
LPS-48193 add link to commented article
LPS-48193 show relative dates

Show relative dates (e.g. "38 minutes ago") instead of absolute
ones (e.g. "Jun 3 2014").
LPS-48193 add a backURL link when viewing articles
LPS-48193 add visual clue to navigation
LPS-48193 order alphabetically
LPS-48193 Change constants values to make them more similar to liferay workflow in case someday we migrate this
LPS-48193 Create STATUS_ANY (with the same value as liferay workflow) to represent when we don't care about the status. STATUS_NONE is used to make explicit that there's no status (to represent the limits of the workflow for the transitions, for example)
LPS-48193 Format source
LPS-48193 Since KBComments don't have permissions (and we don't need them either) we just need to check permission on the VIEW_KB_FEEDBACK and we don't need any custom finder.