[v3] Drop legacy object upload endpoints

[psrok1]

Your checklist for this pull request

• [x] I've read the contributing guideline.
• [x] I've tested my changes by building and running the project, and testing changed functionality (if applicable)
• [ ] I've added automated tests for my change (if applicable, optional)
• [ ] I've updated documentation to reflect my change (if applicable)

What is the current behaviour?

See https://github.com/CERT-Polska/mwdb-core/issues/304 (Use POST /api/file for uploading objects instead of deprecated POST/PUT /api/file/<parent>)

What is the new behaviour?

This PR removes legacy POST/PUT /api/<type>/<parent> endpoints

Minimum supported mwdblib version: https://github.com/CERT-Polska/mwdblib/releases/tag/v3.3.0