Add Kanji OCR to make a proper handwritten based dictionary

[gabrielglbh]

As a niche addition to the app, we could create a section solely to search new kanji and see its meaning through Jisho API, a dictionary. The user could add that kanji to whatever KanList he or she wants and get to study it right away.

Needs:

• tflite
• Pre-trained Kanji Tensorflow Model (from this repo) thanks to ichisadashioko.
• Canvas to paint the unknown character

[gabrielglbh]

We can use this issue to change the color of the canvas accordingly to the selected theme and not always yellow.