Dynamic partitioning support

Some new devices (Android 10+) have dynamic partitions. Instead of flashing to a GPT partition, fastboot flashes to a dynamic partition.

Dynamic partitioning follows a different format from GPT and LVM2 so it isn't already implemented in postmarketOS. Devices that use dynamic partitioning might be incompatible unless the super partition gets flashed with the rootfs. Retrofit devices with the same name for a super partition and logical partition might need to be flashed using the adb shell or downgraded to Android 9. The LineageOS 18.1 build for google-sargo expects dynamic partitions, requiring the user to sideload Android 11 before reinstalling it.

This merge request adds dynamic partitioning support. This would allow testers to flash new devices using fastboot instead of the root shell, and make it easier to switch back and forth between other, working custom ROMs.

Important things to note:

• This MR adds a new package.
• I created a Gitlab repository for the package.
• The added package contains mkinitfs configuration. There is no subpackage that excludes it.

main/make-dynpart-mappings/10-setup-dynamic-partitions.files

+/usr/bin/make-dynpart-mappings