Add api and full feature flags to tuono_lib crate

[Valerioageno]

tuono_lib crate

I could be useful creating a crate features = ["full", "api"] flag for the Cargo.toml manifest. This in order to skip the load of the V8 engine, reqwest crate and the vite proxies, speeding up the build process.

tuono crate

The tuono CLI will also read what feature is enabled and will then turn the project in fullstack or api-only mode.

[Valerioageno]

POC.

For the final build, the following are the required tasks:

• create the e2e test for the tuono_lib crate (Create integration tests for tuono_lib crate #203)
• Add support for the CLI to the api-only mode
• Add api | ssr | full feature flags to tuono_lib+ e2e test