Move files into /cmake/ instead of a cppbessot subdir of it

cmake/dbGenSqlDDL.cmake

@@ -0,0 +1,27 @@
+include_guard(GLOBAL)
+
+include("${CMAKE_CURRENT_LIST_DIR}/dbGenerationCommon.cmake")
+
+function(cppbessot_add_db_gen_sql_ddl_target version)
+  # Purpose: Register SQL DDL snapshot generation target for supported backends.
+  # Inputs:
+  #   - version: Schema version to generate for.
+  #   - CPPBESSOT_ODB_EXECUTABLE: Path to `odb` compiler.
+  # Outputs:
+  #   - CMake target: `db_gen_sql_ddl` (EXCLUDE_FROM_ALL).
+  #   - Files under `<version>/generated-sql-ddl/{sqlite,postgre}`.
+  cppbessot_validate_schema_version("${version}")
+  cppbessot_get_version_dir(_version_dir "${version}")
+
+  add_custom_target(db_gen_sql_ddl
+    COMMAND "${CMAKE_COMMAND}"
+            -DCPPBESSOT_ODB_EXECUTABLE=${CPPBESSOT_ODB_EXECUTABLE}
+            -DCPPBESSOT_VERSION_DIR=${_version_dir}
+            -P "${CMAKE_CURRENT_LIST_DIR}/scripts/run_odb_sql_ddl.cmake"
+    DEPENDS db_gen_cpp_headers
+    COMMENT "Generating SQL DDL snapshots for ${version} (sqlite + postgre)"
+    VERBATIM
+  )
+
+  set_target_properties(db_gen_sql_ddl PROPERTIES EXCLUDE_FROM_ALL TRUE)
+endfunction()