[url_launcher] Replace primary APIs with cleaner versions (flutter#5310)

[local_auth] Fix default deviceSupportsBiometrics (flutter#5321)

[local_auth] Fix getEnrolledBiometrics returning non-enrolled biometr…

…ics on Android. (flutter#5309)

[image_picker] Migrate iOS to Pigeon and improve state handling (flut…

…ter#5285)

[video_player] Add setClosedCaptionFile method to VideoPlayerControll…

…er (flutter#5105)

[various] Replaces manual hashing with Object.hash (flutter#5314)

[various] Replaces manual hashing with Object.hash (flutter#5314)

[various] Replaces manual hashing with Object.hash (flutter#5314)

[various] Replaces manual hashing with Object.hash (flutter#5314)

[image_picker] Added image_picker_for_windows. (flutter#4863)