Bug 2358 - Remove tests json to cnsn and add tests json to nn

Bug 2358 - Remove tests json to cnsn and add tests json to nn

Tests of codecs are included in codecs yangtools yang-data-codec-gson and yang-data-impl but
we test codec on input data and also with presentation of Rest path.

* remove all tests json to composite node and simple node
* rewrite json leafref input tests from comp and simple node to normalized node
  * we're testing REST provider URI path translator with payload
* add test for test data in json with identityref to normalized node
  * positive test
  * test data in builded normalized node with data in json
    * used identityref type to reference an existing identity
* add test for test data in json with leafref to normalized node
  * positive test
  * test data in builded normalized node with data in json
    * used leafref type to reference particular leaf instance in the data tree
* add test for test data in json with more type of nodes and values
  * positive tests
    * test normalized node from json with:
      * simple data in list
      * simple data in container
      * multiple items in leaf-list
      * multiple items in list
      * empty leaf
      * augmented data
  * negative tests
    * test fail on bad top level elements
      * contains 3 situations
    * test fail for null data
      * empty leaf-list
      * leaf without any value
    * test on build normalized node with blank json
    * test fail with different namespaces
    * test fail because of unsupported format of json
    * test on invalid URI character

Change-Id: Icb5ff5d11843123c79859a0c75d7df7bad8a0b44
Signed-off-by: Jakub Toth <jatoth@cisco.com>