This commit creates a temporary directory for the defaultDepvolver()
if no cacheDir is given. This ensures that we do not clutter the
current working directory with `platform:foo` cache directories
that `solver.Depvolve()` creates.
Note that this is only tested indirectly via the integration test
in `test_container.py:test_container_builds_image()` that checks
that the output directory is clean.
This commit adds a new testutil.MockCommand() helper that will
mock a command in $PATH to allow easier testing of e.g. the
`image-builder-cli build` comamnd that will invoke osbuild.
This commit provides a `blueprintload` package that can be used
to load blueprints from json/toml from a path. This will be used
in `bootc-image-builder` and `image-builder-cli` and should
eventually be merged into `images`.
This commit adds a new generic `manifestgen` package that can be
used to generate osbuild manifests. It works on a higher level
then the low-level `manifest` package from `images` and provides
plugable resolvers and a streamlined API.
This package is meant to be moved to the `images` library eventually.
