fix: Enable additional features on c2pa-c-ffi (#1287)

* fix: Add some features

* fix: Add some features

* fix: Make pdf feature available too

Author: tmathern

c2pa_c_ffi/Cargo.toml

@@ -20,12 +20,14 @@ crate-type = ["cdylib", "staticlib", "rlib"]
 [features]
 file_io = ["c2pa/file_io"]
 rust_native_crypto = ["c2pa/rust_native_crypto"]
+pdf = ["c2pa/pdf"]
 
 [dependencies]
 c2pa = { path = "../sdk", version = "0.58.0", default-features = false, features = [
     "add_thumbnails",
     "fetch_remote_manifests",
     "file_io",
+    "pdf"
 ] }
 scopeguard = "1.2.0"
 serde = { version = "1.0", features = ["derive"] }