fix!: Major improvements to `kraft cloud compose`

[nderjung]

Prerequisite checklist

• [x] Read the contribution guidelines regarding submitting new changes to the project;
• [x] Tested your changes against relevant architectures and platforms;
• [x] Ran make fmt on your commit series before opening this PR;
• [ ] Updated relevant documentation.

Description of changes

This PR includes major fixes and improvements which increase the compatibility of using kraft cloud compose against existing compose projects.

This series of commits largely include numerous fixes to the creation (building) of images as well as some partial refactors to the kraft cloud compose up subcommand for better compatibility. Additionally, the following new features are available:

• Dynamically building working directories and projects without the need for a Kraftfile and only the presence of a Dockerfile;
• Introduce a --runtime flag allowing users to specify an alternative pre-built Unikraft unikernel runtime to be used when images are dynamically built from a Dockerfile;
• Introduce a --no-build flag to kraft cloud compose up to prevent the build step from occuring before instance instantiation;
• Preliminary support for an --entrypoint flag which is used to signal when to use arguments supplied in the existing OCI image and when to overwrite them.

[craciunoiuc]

What would be the alternative to this then? Using the internal IP everywhere?

[nderjung]

All instances in your account can communicate via internal networking.