Incorrect format on the config files does not show error message

[patriciareinoso]

Describe the bug

When the upf_config.json or the gnb_config.json files do not have the correct format, the error message is not shown.

To Reproduce

1. Put invalid content in the upf_config.json file
2. Run the NMS server
3. Try to create a Network Slice

Same for the gnb_config.json file

Expected behavior

The error messages is shown as soon as we open the create Network Slice modal. The same way as it is done when the files contain empty lists.

Screenshots

Logs

We can only see the failure in the logs:

Failed to read UPF config file: SyntaxError: Unexpected token 's', "[
somethng
]
" is not valid JSON
    at JSON.parse (<anonymous>)
    at handleGET (webpack-internal:///(api)/./pages/api/upf.ts:28:34)
    at upf (webpack-internal:///(api)/./pages/api/upf.ts:14:19)
    at /home/reinoso/dev/repos/sdcore-nms/node_modules/next/dist/compiled/next-server/pages-api.runtime.dev.js:21:3039
    at /home/reinoso/dev/repos/sdcore-nms/node_modules/next/dist/server/lib/trace/tracer.js:133:36
    at NoopContextManager.with (/home/reinoso/dev/repos/sdcore-nms/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:7062)
    at ContextAPI.with (/home/reinoso/dev/repos/sdcore-nms/node_modules/next/dist/compiled/@opentelemetry/api/index.js:1:518)