feat(project-model): provide flag for no deps

[snprajwal]

A Cargo project can now be built without any dependency metadata being fetched. This classifies as a breaking change for the ra_ap_project_model public API, since we introduce a new field into the config struct, and a new configuration option for the analyzer.

Fixes #19518

[davidbarsky]

have a naming nit about the configuration option.

[Veykril]

Welp

[snprajwal]

have a naming nit about the configuration option.

@davidbarsky I had the same quandary, but I decided to go with noDeps so that we can derive Default with the correct value in the equivalent struct field (false by default). Using fetchDeps would either require us to impl Default explicitly, or have a disparity between the naming across the r-a config and internal struct.

[davidbarsky]

A manual Default implementation is fine. I'd prefer a slightly better user experience over a manual implementation. If we want to be really future-proof, this should probably be an enum

Regardless, I can flip naming in a followup PR.

[BenjaminBrienen]

You might call it offline if you want the feature to cover other use cases intended for an offline workflow. The fact that it is --no-deps could be an implementation detail of offline mode.

[davidbarsky]

Lukas points out that this mirrors Cargo, so I won't bother changing it.