refactor can_handle function to containerd-shim-wasm

[dierbei]

Based on @Mossaka suggestion, can_handle function appears to duplicate the code several times.

We were able to move this function into container-shim-wasm.

The function is used in all of the following places and has the same functionality:

runwasi/crates/containerd-shim-wasmedge/src/executor.rs

Lines 26 to 28 in d0a1a1c

	fn exec(&self, spec: &Spec) -> Result<(), ExecutorError> {
	match can_handle(spec) {
	Ok(()) => {

runwasi/crates/containerd-shim-wasmedge/src/executor.rs

Lines 60 to 62 in d0a1a1c

	fn validate(&self, spec: &Spec) -> std::result::Result<(), ExecutorValidationError> {
	match can_handle(spec) {
	Ok(()) => Ok(()),

runwasi/crates/containerd-shim-wasmtime/src/executor.rs

Lines 29 to 31 in 7e978ed

	fn exec(&self, spec: &Spec) -> Result<(), ExecutorError> {
	match can_handle(spec) {
	Ok(()) => {

runwasi/crates/containerd-shim-wasmtime/src/executor.rs

Lines 56 to 58 in 7e978ed

	fn validate(&self, spec: &Spec) -> std::result::Result<(), ExecutorValidationError> {
	match can_handle(spec) {
	Ok(()) => Ok(()),

We might be able to move him to the crates/containerd-shim-wasm/src/exector_util.rs file.