Add `frozen_record` to query static data in ActiveRecord-style

[marcoroth]

This pull request adds the frozen_record gem to allow us to query the static data in an ActiveRecord-style way. This might help to implement features like #118 where we want to import/update/query data from our static YAML files.

You can do something like:

video = Static::Video.find_by(video_id: "r78H-QBkxyk")

Which will give you something like:

=>
#<Static::Video:0x00000001252a7d78
 @attributes=
  {"title"=>"Opening Keynote: MythBuster",
   "raw_title"=>"Opening keynote by Matz: MythBuster",
   "speakers"=>["Yukihiro \"Matz\" Matsumoto"],
   "event_name"=>"Euruko 2022",
   "published_at"=>"2022-10-20",
   "description"=>
    "The opening keynote by Yukihiro Matsumoto from Euruko 2022.\n\nTo watch with closed captions, view the livestream recording: https://www.youtube.com/watch?v=reVGR35H264&t=2010s",
   "video_id"=>"r78H-QBkxyk"}>

Which allows you to access all the attribute like in an ActiveRecord model:

rubyvideo(dev)> video.title
=> "Opening Keynote: MythBuster"

rubyvideo(dev)> video.speakers
=> ["Yukihiro \"Matz\" Matsumoto"]

And the same for all the playlists, speakers, organizations and videos_to_ignore files we have.