feat: Add `signstar-config` crate to handle Signstar host configs

.lycheeignore

Cargo.lock

Cargo.toml

signstar-config/Cargo.toml

signstar-config/README.md

signstar-config/examples/get-nethsm-credentials.rs

signstar-config/src/admin_credentials.rs

signstar-config/src/config.rs

signstar-config/src/error.rs

signstar-config/src/lib.rs

signstar-config/src/non_admin_credentials.rs

signstar-config/src/utils.rs

signstar-config/tests/admin_credentials/mod.rs

signstar-config/tests/config/mod.rs

signstar-config/tests/fixtures/admin-creds-simple.toml

signstar-config/tests/fixtures/signstar-config-full.toml

...star-config/tests/fixtures/signstar-config-plaintext.toml

signstar-config/tests/integration.rs

signstar-config/tests/non_admin_credentials/mod.rs

signstar-config/tests/utils/mod.rs