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

cmake/dbGenCpp.cmake

@@ -0,0 +1,35 @@
+include_guard(GLOBAL)
+
+include("${CMAKE_CURRENT_LIST_DIR}/dbGenerationCommon.cmake")
+
+function(cppbessot_add_db_gen_cpp_target version)
+  # Purpose: Register C++ model generation target using checked-in templates.
+  # Inputs:
+  #   - version: Schema version to generate for.
+  #   - CPPBESSOT_NPX_EXECUTABLE: Path to `npx`.
+  # Outputs:
+  #   - CMake target: `db_gen_cpp_headers` (EXCLUDE_FROM_ALL).
+  #   - Files under `<version>/generated-cpp-source`.
+  cppbessot_validate_schema_version("${version}")
+  cppbessot_get_version_dir(_version_dir "${version}")
+
+  set(_openapi_file "${_version_dir}/openapi/openapi.yaml")
+  set(_template_dir "${_version_dir}/openapi/templates/cpp-odb-json")
+  set(_template_config "${_template_dir}/config.yaml")
+  set(_output_dir "${_version_dir}/generated-cpp-source")
+
+  add_custom_target(db_gen_cpp_headers
+    COMMAND ${CMAKE_COMMAND} -E make_directory "${_output_dir}"
+    COMMAND "${CPPBESSOT_NPX_EXECUTABLE}" @openapitools/openapi-generator-cli generate
+            -i "${_openapi_file}"
+            -g cpp-restsdk
+            -t "${_template_dir}"
+            -c "${_template_config}"
+            -o "${_output_dir}"
+            --global-property models
+    COMMENT "Generating C++ model headers/sources for ${version}"
+    VERBATIM
+  )
+
+  set_target_properties(db_gen_cpp_headers PROPERTIES EXCLUDE_FROM_ALL TRUE)
+endfunction()