Keep hidden headers (header_layout 100) out of the JSON

Applied on all three render paths: stdWrap.if rule on
lib.contentElementWithHeader (before the plugin copies), the same rule in
the container element definitions, and a HiddenHeaderProcessor behind the
nb content-blocks data processor. headerLayout itself stays in the payload
so the front end can tell why the header is empty.

packages/vitec/Configuration/TypoScript/Headless/vitec_containers.typoscript

@@ -72,10 +72,22 @@ tt_content.vitec_cols_50_50 {
             }
         }
 
+        # header_layout 100 = "Hidden": header, subheader and headerLink stay
+        # out of the JSON (same rule as lib.contentElementWithHeader).
         header = TEXT
         header.field = header
+        header.stdWrap.if {
+            value = 100
+            equals.field = header_layout
+            negate = 1
+        }
         subheader = TEXT
         subheader.field = subheader
+        subheader.stdWrap.if {
+            value = 100
+            equals.field = header_layout
+            negate = 1
+        }
         headerLayout = INT
         headerLayout.field = header_layout
         headerPosition = TEXT
@@ -87,6 +99,11 @@ tt_content.vitec_cols_50_50 {
                 parameter.field = header_link
                 returnLast = result
             }
+            stdWrap.if {
+                value = 100
+                equals.field = header_layout
+                negate = 1
+            }
         }
         tx_vitec_bg_variant = TEXT
         tx_vitec_bg_variant.field = tx_vitec_bg_variant