Implement RFC 11: Redesigning Wasmtime's APIs (#2897)

Implement Wasmtime's new API as designed by RFC 11. This is quite a large commit which has had lots of discussion externally, so for more information it's best to read the RFC thread and the PR thread.

crates/c-api/src/error.rs

@@ -1,6 +1,5 @@
-use crate::{wasm_name_t, wasm_trap_t};
+use crate::wasm_name_t;
 use anyhow::{anyhow, Error, Result};
-use wasmtime::Trap;
 
 #[repr(C)]
 pub struct wasmtime_error_t {
@@ -9,12 +8,6 @@ pub struct wasmtime_error_t {
 
 wasmtime_c_api_macros::declare_own!(wasmtime_error_t);
 
-impl wasmtime_error_t {
-    pub(crate) fn to_trap(self) -> Box<wasm_trap_t> {
-        Box::new(wasm_trap_t::new(Trap::from(self.error)))
-    }
-}
-
 impl From<Error> for wasmtime_error_t {
     fn from(error: Error) -> wasmtime_error_t {
         wasmtime_error_t { error }