cli: make credentials test interactive; add credentials test command

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ia87db118ca58c66841265f34253b08ed6a6a6964

src/main.rs

@@ -188,6 +188,10 @@ async fn main() -> Result<(), PakkerError> {
             set_args.modrinth_token,
             set_args.gh_access_token,
           )
+          .await
+        },
+        Some(cli::CredentialsSubcommand::Test) => {
+          cli::commands::credentials_test::execute().await
         },
         None => {
           cli::commands::credentials::execute(