flash: Add sapphire flashing script

Description

Add flashing fastboot flashing script for sapphire.

Issue(s)

https://gitlab.e.foundation/e/devices/backlog/-/issues/1339

Screenshots

Technical details

Tests

Confirmed flashing script works locally and flashes all relevant partitions.

Issues

10 commandments of code reviews

👪 ❤️ https://gitlab.e.foundation/internal/wiki/-/wikis/mobile-team/guidelines/Code-review