feat(card10_nickname): more detailed battery level

Indicates battery level by (partial) filling of the battery symbol: full == filled symbol, near empty == empty battery symbol, etc.

It's still not perfect (battery voltage is not the best state of charge measure out there), but IMHO better than a colour-only indicator

Looks good to me! Thanks for keeping our codebase clean.

However, I'm only a bot - so a human will still have to approve this request.

added 3 - Preload 6 - Needs Review labels

LGTM

added 6 - Needs Testing label

changed milestone to %v1.9

removed 6 - Needs Review label

merged

mentioned in commit 2ef00eb0