Grow system partition during boot when started from USB
Currently, Tails Installer creates a system partition if size 4 GiB or 8 GiB during installation. It would vastly increase the size of the USB image if we would include such a big partition in it, and unnecessarily so, because the partition is mostly empty. The plan is to instead ship a USB image of minimum size, and increase the size of the system partition during the first boot of the device.
Feature Branch: feature/15292-repartition
Parent Task: #15293 (closed)