Teach pipeline validator abount terminate processor (#857)

Allow to include the terminate processor in pipelines.

Co-Authored-By: Dan Kortschak <dan.kortschak@elastic.co>

spec/changelog.yml

@@ -18,6 +18,9 @@
     - description: Allow to override default deployment mode.
       type: enhancement
       link: https://github.com/elastic/package-spec/pull/854
+    - description: Add `terminate` processor to list pipeline spec.
+      type: enhancement
+      link: https://github.com/elastic/package-spec/pull/857
 - version: 3.3.1
   changes:
     - description: Add validation rule to ensure security capability is added if there is any security rule asset.

spec/integration/elasticsearch/pipeline.spec.yml

@@ -48,6 +48,7 @@ spec:
         # set_security_user: false # Applicable to packages?
         sort: { type: object }
         split: { type: object }
+        terminate: { type: [object, "null"] }
         trim: { type: object }
         uppercase: { type: object }
         urldecode: { type: object }
@@ -109,6 +110,10 @@ spec:
       $ref: "#/definitions/processors"
 
 versions:
+  - before: 3.3.2
+    patch:
+      - op: remove
+        path: /definitions/processor/properties/terminate # remove terminate processor validation
   - before: 3.1.0
     patch:
       - op: remove

test/packages/good_v3/elasticsearch/ingest_pipeline/default.yml

@@ -5,3 +5,4 @@ processors:
 - set:
     field: error.message
     value: '{{ _ingest.on_failure_message }}'
+- terminate: