XOS/NEM charts, use a global registry var, split docker image name/tag/pullPolicy

Change-Id: I7f3457882830de050d1357254fc5483faf91d03f
diff --git a/xos-tools/kafkacat/Chart.yaml b/xos-tools/kafkacat/Chart.yaml
index dadfad4..39e9fb5 100644
--- a/xos-tools/kafkacat/Chart.yaml
+++ b/xos-tools/kafkacat/Chart.yaml
@@ -15,4 +15,9 @@
 
 name: kafkacat
 description: A Helm chart for kafkacat
-version: 1.0.0-dev
+icon: https://kafka.apache.org/images/logo.png
+
+version: 1.0.0
+
+# version of confluentinc/cp-kafkacat container
+appVersion: 4.1.2