Implement the Wasm exception-handling proposal #1137
Description
This is about adding support for the exception-handling Wasm proposal.
The exception-handling Wasm proposal has been recently moved to Phase 4 and thus stabilization can be expected to happen soon.
Having exception-handling support in wasmi will be an enabler (in parts) for using Wasmi for Wasm blobs resulting from compiling programming languages that have built-in exception handling support such as Java, JS etc.