fix: Start adding stuff for nulls

risk: low

Author: fiedlr

packages/gooddata-sdk/tests/catalog/expected/declarative_ldm_with_sql_dataset.json

@@ -40,7 +40,8 @@
             "description": "Campaign channel id",
             "tags": [
               "Campaign channels"
-            ]
+            ],
+            "isNullable": false
           },
           {
             "id": "campaign_channels.category",

packages/gooddata-sdk/tests/catalog/expected/declarative_pdm_ldm_request.json

@@ -10,7 +10,8 @@
         {
           "data_type": "STRING",
           "isPrimaryKey": true,
-          "name": "campaign_channel_id"
+          "name": "campaign_channel_id",
+          "isNullable": false
         },
         {
           "data_type": "INT",

packages/tests-support/fixtures/demo_declarative_hierarchy.json

@@ -2519,6 +2519,7 @@
                   "labels": [],
                   "sourceColumn": "campaign_channel_id",
                   "sourceColumnDataType": "STRING",
+                  "isNullable": false,
                   "tags": [
                     "Campaign channels"
                   ],