The docker compose V2 spec no longer accepts `network_mode: bridge`,
which means we can no longer override the network configuration of
the `balena-supervisor` service for tests.
For this reason we now create a separate service to run the built
supervisor `balena-supervisor-sut` and run API tests against this
service instead of the default `balena-supervisor`.
Change-type: patch
This PR changes the way the supervisor reads and writes files from /mnt/boot. Reads will
now use the [fatrw utility](https://github.com/balena-os/fatrw/) as a way to minimize corruption of
files in the boot partition, and thus preventing possible bricking of the device.
Since this basically changes the way a lot of configurations are read, this work was being blocked because of
the way tests were being done. While there still remain a couple of legacy tests to be migrated, this PR disables
test:legacy tests when running npm run test, as the work on refactoring those tests is in progress (see #2048) and
fatrw integration is of higher priority.
Change-type: minor