CiviCase : Move-to-trash feature for Cases and Activities

According to our Case Mgmt domain experts (PHP-BC), users should NOT be able to physically delete cases OR delete activiites from cases. Replace existing record-delete behavior for these 2 record types as follows:

1. Add an is_deleted column to civicrm_activity and civicrm_case (tinyint default 0) with index

2. Modify Case Dashboard, Find Cases and Case >> Tab.php to exclude cases where is_deleted = 1

3. Add a search criteria field to Find Cases search conditionally - the field is only displayed for users with "administer CiviCRM" permission:

• [ ] Deleted Cases
  When checked, search query logic is switched to exclude cases where is_deleted = 0

4. Modify Activity query in Case Dashboard, Find Cases, and View Case pages to exclude activities where is_deleted = 1

5. Add search criteria to View Cases >> Activities search conditionally - the field is only displayed for users with "administer CiviCRM" permission:

• [ ] Deleted Activities
  When checked, search query logic is switched to exclude activities where is_deleted = 0