This splits `App`, `Network`, `Service` and `Volume` which used to be
defined as classes into an interface and a class implementation that is
not exported. This will allow to work with just the types in some cases
and prevent circular dependencies when importing.
Change-type: patch
This updates balena lint to the latest version to enable eslint support
and unblock Typescript updates. This is a huge number of changes as the
linting rules are much more strict now, requiring modifiying most files
in the codebase. This commit also bumps the test dependency `rewire` as
that was interfering with the update of balena-lint
Change-type: patch
