Add search image by thumbnail

[shikendon]

Not decided what ways to search yet. Maybe Google Images or API from some gallery websites.

Niconico API: https://ext.nicovideo.jp/api/getthumbinfo/sm26065322

• 放課後のプレアデス　歌いました【鹿乃】
  
  Result: Search full resolution wallpaper.
• +♂歌ってみた　ver96猫 ※自重なし
  
  Result: Search full resolution wallpaper.
• 【L.I.N.E】lead is new emotion【オリジナル】
  
  Result: Filter out non-anime images.

[shikendon]

Already implemented pixiv images search integration.