New licenses should have a default value for end date semantics

Purpose/Overview:

For simplicity and consistency new licenses should have a default value of "implicit" for the end date semantics. This should be interpreted as meaning openEnded == false.

This will make it easier to query for licenses that are/are not OpenEnded

Scenario 1:
Given: a new license
When: the user saves the license for the first time and has never checked or unchecked the "open ended" check box in the license creation form
Then: the license will be created with endDateSemantics == implicit

Scenario 2:
Given: a license with endDateSemantics == implicit
When: the user views or edits the license
Then: the Open Ended value will == false

Scenario 3:
Given: a license simple search dashboard widget
When: the user sets a filter of "Open ended?" != Open ended
Then: the widget will display all licenses that have endDateSemantics != open_ended

Dev breakdown

1. add function on save() to change unset values to implicit
2. cleanup script to change any unset values
3. add timer to module descriptor (to implement cleanup)
   1. initial testing with helloworld()-like stuff 
4. add integration test to check the cleanup function (documentation: https://wiki.folio.org/display/ERM/ERM+Orientation+Reference)