Icon Request: Battery Icon(s)

When using this library (it is awesome!) also for hardware wallets, also the need for a battery icon arises, to inform the user when it is time to recharge the device.

Currently we (Specter DIY project: https://github.com/cryptoadvance/specter-diy) use the LVGL built-in symbols for that, which can be found e.g. here:
https://docs.lvgl.io/9.0/overview/font.html (chapter: special fonts)
