Function install_package 

pub fn install_package(
    project_dir: &Path,
    registry: &NetworkRegistry,
    name: &str,
    options: &InstallOptions,
) -> PkgResult<InstalledPackage>

Install a package: download, extract, and update the manifest + lockfile.

project_dir is the directory containing bock.package (and where the .bock/ subtree will live). registry must already be configured with the caller’s cache directory and, optionally, an auth token.