Feature soft autoassignment (#789)

* Repository layer and database migration
* Changed target filter management to update auto assignment action type together with distribution set, extended mgmt API, adapted auto assign checker/scheduler, changed auto assign distribution set select table to combobox, added filter functionality (needs refactoring)
* Refactored auto assignment dialog window, added soft/forced option group, restructured action type option group layout
* Added forced icon to target filter table autoassignment cell for the forced auto assign actions
* First working draft of distribution set select combobox for auto assignment window
* Optimised filtering queries, added alphabetical sorting on distribution set name and version
* Refactoring of distribution bean query for lazy loading
* Distribution set combobox refactoring and comments
* Added verification of auto assign distribution set validity (completed, not deleted), exdended target filter query fields with auto assign action type field, added rsql filter tests, added repository layer tests
* Added mgmt API tests
* Changed target filter rest docu tests to include auto-assignment type
* Updated hawkbit docs with auto-assignment description
* Added debouncing to key and value input fields of metadata popup layout to get rid of unnecessary value change events, removed redundant set value call in common dialog window, minimizing the repaint components calls
* Fixed sonar findings
* Reverted changes of common dialog window validaton, setting the value of the field explicitly as before, until we rethink the whole concept of validaton mechanism
* Fixed review findings
* Removed rsql filtering by filter auto-assign action type, due to missing conversion of disallowed timeforced action type
* Small fix regarding usage of page request
* Updated sql script version for flyway
* Extended tests for soft deleted distribution sets for auto-assignment and filter string within distribution set specification builder

Signed-off-by: Bogdan Bondar <Bogdan.Bondar@bosch-si.com>

docs/content/ui.md

@@ -108,6 +108,7 @@ Custom target filter overview and filter management.
 - Custom target filter allows user to filter targets by defining custom query.
 - Displays custom target filter list and user can search any particular filter.
 - Create, update and delete features are supported for target filters.
+- Auto assignment of a distribution set to filtered targets.
 
 ### How to Filter
 The basic syntax to filter is: `field<basic_operator>value <composite_operator> field<basic_operator>value <...>`
@@ -139,3 +140,12 @@ name==CCU* and updatestatus==pending
 (updatestatus!=error or updatestatus!=pending) and (name==\*CCU\* or description==\*CCU\*) | Gives all targets that either have the term ‘CCU’ in their name or their description and that either have the _update status_ not in state error or pending.
 
 ![Target Filter Management view](../images/ui/target_filter.png)
+
+### Auto assignment
+It is possible to assign some distribution set with different action types (_forced_ or _soft_) to all targets that belong to the corresponding custom target filter, including the ones, that are registered later on.
+
+In order to activate the auto-assignment, one should first click on _Auto assignment_ cell in Custom Filters table, and then check the corresponding checkbox. After that, the action type and distribution set for auto-assignment should be selected and confirmed.
+
+As long as the auto-assignment stays active, the scheduler will try to assign selected distribution set to corresponding custom filter targets, that have never seen it before. 
+
+![Auto assignment](../images/ui/target_filter_auto_assignment.png)