Add SPDX license tags to templates

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modules/ca/src/template/top/caClientApp/caExample.c

@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 1998 Argonne National Laboratory
+//
+// SPDX-License-Identifier: EPICS
+
 /*caExample.c*/
 #include <stddef.h>
 #include <stdlib.h>