Support Pinyin tone numbers as well as accent marks

[kshehata]

Is your feature request related to a problem? Please describe.
For more effective learning, I like to set Anki to require me to type in my answer on the front of the card, to be compared when I flip to the back. While accent markers for tones are much nicer to display, they're much more difficult to type and make comparison with the correct answer difficult. Ideal solution would be to allow pinyin with accent marks and pinyin with tone numbers in the same note.

Describe the solution you'd like
Have a separate field type for pinyin with tone numbers. If that field is present, then the pinyin with the tone numbers is applied to it.

Describe alternatives you've considered
We could have just an option for whether to use accent marks or tone numbers, but ideal would be to support both at the same time. Tone numbers is for typing answers, and accents are for display.

Additional context
Here's an example of an existing card from another deck.

[kshehata]

Another example showing what happens if you get the answer wrong, so you understand the comparison mechanism:

[kshehata]

Duplicate of #56