implement serde for Key Binding

[david-allison]

Pull Request template

Purpose / Description

Key Bindings need to be serialized and deserialized from preferences

This brings in the code for #8078 to handle this aspect of #6052

How Has This Been Tested?

Should be non-functional, unit tests lifted from the PR

Checklist

• You have not changed whitespace unnecessarily (it makes diffs hard to read)
• You have a descriptive commit message with a short title (first line, max 50 chars).
• Your code follows the style of the project (e.g. never omit braces in if statements)
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[mikehardy]

Unit test failure looks legit ?

        Caused by:
        java.lang.AssertionError: expected:<com.ichi2.anki.reviewer.PeripheralKeymap$MappableBinding@8c1b> but was:<com.ichi2.anki.reviewer.PeripheralKeymap$MappableBinding@745f>
            at org.junit.Assert.fail(Assert.java:89)
            at org.junit.Assert.failNotEquals(Assert.java:835)
            at org.junit.Assert.assertEquals(Assert.java:120)
            at org.junit.Assert.assertEquals(Assert.java:146)
            at com.ichi2.anki.reviewer.BindingAndroidTest.assertBindingEquals(BindingAndroidTest.kt:56)
            at com.ichi2.anki.reviewer.BindingAndroidTest.testFromString(BindingAndroidTest.kt:42)

[mikehardy]

LGTM! Also, because of this I learned of Rust "traits" via lookup of "what is serde" and seeing serde.rs 🤓

[david-allison]

LGTM! Also, because of this I learned of Rust "traits" via lookup of "what is serde" and seeing serde.rs 🤓

modem = modulator-demodulator
serde = serialiser-deserialiser