feat(tools): Introduce pass-compatible wrapper using Cloud KMS

Adds a shell script that supports a subset of the 'pass' interface for
compatibility with kontemplate, and wraps kontemplate in a script that
places this version on the PATH.

This makes it possible to use Cloud KMS encrypted secrets with kontemplate.

tools/bin/__dispatch.sh

@@ -22,6 +22,9 @@ case "${TARGET_TOOL}" in
   stern)
     attr="stern"
     ;;
+  pass)
+    attr="tazjin.kms_pass"
+    ;;
   *)
     echo "The tool '${TARGET_TOOL}' is currently not installed in this repository."
     exit 1