[Note Editor][Toolbar]: allow custom labels to user-defined buttons

[PetbkA]

Is your feature request related to a problem? Please describe.
I've added <code>, <ol> and <li> tags to Note Editor toolbar, but they all are displayed as "1", "2" and "3". So I have to remember what every number means.

It would be nice if I could change user-defined buttons labels.

Describe the solution you'd like
When adding user-defined button, third field (e.g. "label") will be displayed where I can set custom label.

The problem is that only 1 or 2 characters will fit to label, so there should be:

1. Unicode symbols support;
2. Limit to length of label (e.g. 2 characters)

[welcome]

Hello! 👋 Thanks for logging this issue. Please remember we are all volunteers here, so some patience may be required before we can get to the issue. Also remember that the fastest way to get resolution on an issue is to propose a change directly, https://github.com/ankidroid/Anki-Android/wiki/Contributing

[david-allison]

Thanks for the report!

Already exists in our alpha: https://github.com/ankidroid/Anki-Android/releases (pick Parallel.A)

Duplicates #9077