Remove obsolete guest error handling

- Remove guest_err.rs from hyperlight_host (replaced by new error handling)
- Remove guest_err.rs from hyperlight_guest_bin (replaced by new error handling)
- Update func/mod.rs to remove obsolete import

Signed-off-by: Ludvig Liljenberg <[email protected]>

Author: ludfjig

src/hyperlight_guest_bin/src/guest_err.rs

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-/// Functionality to check for errors after a guest call
-pub(crate) mod guest_err;
 /// Definitions and functionality to enable guest-to-host function calling,
 /// also called "host functions"
 ///