Decouple some more Config methods from each other (#4262)

* Decouple some more `Config` methods from each other

This commit decouples validation of stack sizes and guard sizes until
`Engine::new` to avoid odd interactions between the order of invocation
of `Config` methods.

* Fix C API

* Typos

crates/c-api/src/config.rs

@@ -60,8 +60,8 @@ pub extern "C" fn wasmtime_config_epoch_interruption_set(c: &mut wasm_config_t,
 }
 
 #[no_mangle]
-pub extern "C" fn wasmtime_config_max_wasm_stack_set(c: &mut wasm_config_t, size: usize) -> bool {
-    c.config.max_wasm_stack(size).is_ok()
+pub extern "C" fn wasmtime_config_max_wasm_stack_set(c: &mut wasm_config_t, size: usize) {
+    c.config.max_wasm_stack(size);
 }
 
 #[no_mangle]