odb: Move messages checking to odb to fix deps.

The messages checking was set at db level as odb is an interface and
doesn't not have a post-build trigger. Unfortunately there were no
dependencies on other libs besides db such as defin.
So peforms the messages checking at odb level using a custom target.

src/odb/CMakeLists.txt

@@ -81,3 +81,19 @@ if(ENABLE_TESTS)
     odb
   )
 endif()
+
+add_custom_target(
+  odb_messages ${CMAKE_SOURCE_DIR}/etc/find_messages.py > messages.txt
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+  DEPENDS
+    db
+    cdl
+    defin
+    defout
+    lefin
+    lefout
+    zutil
+    gdsin
+)
+
+add_dependencies(odb odb_messages)

src/odb/src/db/CMakeLists.txt

@@ -179,9 +179,3 @@ target_link_libraries(db
         utl_lib
         ${TCL_LIBRARY}
 )
-
-messages(
-  TARGET db
-  OUTPUT_DIR ../..
-  SOURCE_DIR ../..
-)