feat: add custom metadata when a face is recognized

[IliasHad]

Overview

This PR introduces a new capability that allows the system to load custom metadata for known faces and attach it to face recognition results. This feature has been requested by a community user.

Over the face folder, for example, FACE_DIR/Ilias/metadata.json, you can set the custom properties there that will be loaded and indexed when the face of "Ilias" has been recognized.

FACE_DIR/Ilias/metadata.json example file:

{
  "name": "Ilias Haddad",
  "alternate_names": ["Ilias Hadd"],
  "nationalities": ["Netherlands", "Morocco"],
  "date_of_birth": "1989-03-01",
  "place_of_birth": "Dordrecht, Netherlands",
  "height_m": 1.87,
  "positions": ["Centre-back"],
  "current_club": "Union Touarga",
  "club_jersey_number": 20,
  "dual_nationality": true
}

After the video is indexed, each video scene where "Ilias" has been recognized, this is how the video scene text document will be indexed and saved over the vector DB:

This is medium-shot shot featuring Ilias, Ilias (name: Ilias Haddad, alternate_names: Ilias Hadd, nationalities: Netherlands,Morocco, date_of_birth: 1989-03-01, place_of_birth: Dordrecht, Netherlands, height_m: 1.87, positions: Centre-back, current_club: Union Touarga, club_jersey_number: 20, dual_nationality: true

Over the search page, you can search for that video scene using any attributes like current_club: Union Touarga and it'll give back the video scene that we indexed.