Describe the bug
Dropzone doesn't send the correct proposal id to the /proposal/attach:id endpoint.
Error handling is also not proper so even image fails to upload, it shows success.

Steps to Reproduce
Steps to reproduce the behavior:

1. Go to 'Organization'
2. Click on 'Propose Idea'
3. Write proposal details.
4. Save the proposal as a draft.
5. When you see dropzone(file upload section), choose a file to be uploaded.
6. Checkout the error on the API server console.

Expected behavior
It should attach the image as expected.

Screenshots
DetectedBug