Content browser enhancement

[FacoBackup]

• [x] Metadata for selected resource
• [x] Image preview with selection
• [x] Include file metadata when importing file (preview image part of metadata object)
  • [x] Meshes: number of triangles, normal/uv information included or not
  • [x] Images: resolution
  • [x] Audio: track size, quantity of samples like 128kbps