Refactor PR #3410 to drop extra commits.
All credit to @jdelhome3578

This fixes sorting and total ticket count.

The [signal documentation]
(https://github.com/osTicket/osTicket/blob/develop/setup/doc/signals.md)
for the `cron` signal states that the context is `null`. But it was
missing until now (and the `$data` parameter was wrongly forwarded as
`$object`)

In ::isMember(), there is now no reason that a call to ::getMembers() would
fail, so it can be assumed that a QuerySet instance is returned.

This fixes an issue where the `$ht` variable is not properly initialized by
the ORM. It is assumed to be a valid array in the constructor, and its items
are run through the ::set() method. Therefore, if an empty array is
received, the `$ht` variable will remain null, since nothing is ever set.

This also fixes a misspelled variable in the claim dialog if a ticket is
currently assigned to a team only.

Fixes #3194

This is important to show custom statuses with properties.

Set _value in DynamicFormEntryAnswer even when value is empty.

Add a preview tool tip to show list item properties on mouse-over.

Fix a bug where it was impossible to disable ALL collaborators
Change recipients active/total count on update

Allows for ability to access results without the need to call getIterator on
the QuerySet. For example - $this->members->findFirst(array(...));

This commit addresses regression issue brought about by commits 8ab4432f and
eb0ba316 -- where ResultSet processing changed based on caching mode.

With the advent of the MANIFEST file, files which are rewritten when
deployed, such as those which have the GIT hash in the query string to force
browser reloading, were no longer deployed unless the content of those files
changed.

This patch adds a flag to the MANIFEST file to indicate that the file was
rewritten when it was deployed. This allows the file to be deployed and
rewritten again when the deployment is run, but also adds an indication
to the console output to distinguish deploying changes as opposed to
deploying rewrites.

This feature adds a setting to the control panel to require signing in to
view attachments. This is in addition to the security already provided in
the download URLs. Currently, download URLs are signed for a specific help
desk, and automatically expire after about 24 hours. The exact timing is the
following midnight allowing for at least 12 hours cache time.

Administrators can impose this extra security feature to refuse serving
attachment files if the user is not currently signed in. This could prevent
third-party users from viewing an attachment if they were able to get access
to the download URL before it expired.

* Separate primary from extended access members when listing department
  access.

* Add ability to update primary department members role

* Quick staff add - inherit role of the primary department as default role

Add ability get sorted department members. Extended members are sorted, annotated
and cached.

Consolidate agents name sorting in Staff::nsort. The routing expects a query
set.

isMember routine wrongly assumed getMembers returned staff_id indexed
hashtable.

Session backend issues update via write on new session which caused
assertion to fail.

If the Return-Path header does not match the From header, emails are significantly more likely to be blocked by spam filters.

This patch forces the return header to match the from address without having to change php.ini and therefore works properly on servers that have multiple apps sending from multiple email addresses for example shared hosting, multiple support emails in one instance etc.

Add callback filter to standard iteration method to skip deleted items.

Use file id instead of attachment id to unset new
Get new files objects as array

Credit @Jared

Include username when checking if a system email already exists. This
is important for emails that use aliases.

Use org_id to filter users to update on organization delete

If something like members__staff is considered leaving the Team model,
and the `members` relationship is nullable, and the `staff` relationship is
not, in the context of the compiled SQL statement, the second join should
also be considered nullable (LEFT join), because otherwise inconsistent
results would be returned from the query.

In other words, if a count is considered as an annotation to the Team model
instances, Teams with zero members should still be considered as valid teams
and should be selected with such an annotation. Before this patch, however,
the join between TeamMember and Staff would have been an inner join instead
of a LEFT join, which could skew the database results.

This fixes an issue where the CDATA table is updated with the OLD version of
an answer after it is updated. That is, after an answer is updated, the
CDATA table is also updated to reflect the change; however, the old content
of the answer value is used when updating the CDATA value.