feat: add needs_project property

[mr-cal]

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Two things:

1. Refactors the LifecycleCommands classes in a slightly more organized way without changing any existing commands. This is required for snapcraft to define its own Pack command with minimal duplicated code (feat: allow packing a directory snapcraft#4794)
2. Add a needs_project property, which can determine if a project needs to be loaded based on the provided arguments.

Fixes canonical/snapcraft#4769
(CRAFT-2861)

[tigarmo]

nice thanks!

[mr-cal]

Force-pushing so I can rebase