Persist chord memory to song file (community)

[soymonitus]

Same PR as https://github.com/SynthstromAudible/DelugeFirmware/pull/2119 but for community branch

[github-actions[bot]]

Test Results

44 tests  ±0   44 :white_check_mark: ±0   0s :stopwatch: ±0s  8 suites ±0    0 :zzz: ±0   8 files   ±0    0 :x: ±0 

Results for commit 3a41fe89. ± Comparison against base commit a7331a7b.

:recycle: This comment has been updated with latest results.