XWIKI-11681: When you introduce some special character into Breadcrumb-Separator you get an error in Flamingo Theme Editor.

- Reduced specificity by removing unneeded tag

XWIKI-11647: User Index icon disappears after adding an attachment to Main.UserDirectory with a normal user
- Separated the UIExtension from the UserDirectory page to avoid regular users saving it without admin rights.

* Added missing nested exception

- Changed the translations scope to WIKI since Administration Application is also using them

* Added ability to iterate over a list of references (either group or user)
* Added ability to return user data (e.g. user's email) and to programatically skip some entries based on programmatic condition
* Added ability to exclude users/groups

* Improve variable names

* Generify by accepting a list of references as input

XWIKI-11774 : The scope icon for the group displayer is not centered in ...

- after some discussion it has been decided that it is best to use padding: 9px 4px;
-- the values are calculated for a 16x16 icon, an input height of 34px and a border of 25px
-- vertical: 25px - 16px = 9px / 2 = 4.5px
-- horizontal: 34px - 16px = 18px / 2 = 9px

XWIKI-11775: Missing translations keys for Administration's 'User Directory' and 'Applications Panel' sections

- Fixing 'User Directory' section

XWIKI-11775: Missing translations keys for Administration's 'User Directory' and 'Applications Panel' sections

- Fixing 'Applications Panel' section

- Test first that a section ID containing a dot is a document reference before ruling out other options.

* Missing version

* Updated xwiki.properties file with the new config property

* Quote the class name in the XWQL query because it can contain Unicode characters.

* Update the unit tests to prove that Unicode class names are actually supported.

* Exclude a file since it makes jacoco fail

* Exclude a file since it makes jacoco fail

* Exclude a file since it makes jacoco fail

XWIKI-11701: Improve the mail sender script service API when sending mails to a group or to a list of users
* Add functional tests for sending a template mail to a list of users

* Fix remaining functional tests

* Fix administration + faq functional test

* Fix activeinstalls functional test

* Make the modules with outputs use the new simpler way to exclude the verification