fuji: TWRP: add some flags

* TW_FLASH_FROM_STORAGE: flahes zip packages directly from storage instead of copying it to a tmp folder first
* TW_EXTERNAL_*: support for external sd cards (Hikari, this one is for you)
* TW_INCLUDE_FUSE_EXFAT: ExFAT support in TWRP
* TW_MAX_BRIGHTNESS: limits the brightness