[midPoint-git] [Evolveum/midpoint] 12ae77: Revert adding default Item.add method

[mederly]

  Branch: refs/heads/master
  Home:   https://github.com/Evolveum/midpoint
  Commit: 12ae77446748daede49b42f9774b3c552610db1c
      https://github.com/Evolveum/midpoint/commit/12ae77446748daede49b42f9774b3c552610db1c
  Author: Pavol Mederly <mederly at evolveum.com>
  Date:   2020-02-27 (Thu, 27 Feb 2020)

  Changed paths:
    M infra/prism-api/src/main/java/com/evolveum/midpoint/prism/Item.java
    M infra/prism-impl/src/main/java/com/evolveum/midpoint/prism/impl/ItemImpl.java

  Log Message:
  -----------
  Revert adding default Item.add method

This fixes TestArchetypes.

The ultimate reason of the issue was the mess related to various
add(..) methods in Item type hierarchy that lead to incorrect method
being called (after creation of the default add(value) implementation).