Invocation Flow Improvements (Fixes Encoding Problems)

[dOrgJelli]

After seeing the problems described in this PR #947 it occurred to me that the way we have implemented noDecode is incorrect and incomplete.

It does not cover all possible encoding cases:

In order to make the above possible, we need to add the concept of an invoker and an invocable. This will allow us to have different options / return values:

export interface InvokerOptions extends InvokeOptions {
  encodeResult?: boolean;
}

export interface Invoker {
  invoke(
    options: InvokerOptions
  ): Promise<InvokeResult>;
}

export interface InvocableResult extends InvokeResult {
  encoded: boolean;
}

export interface Invocable {
  invoke(
    options: InvokeOptions,
    invoker: Invoker
  ): Promise<InvocableResult>;
}

A rough outline of the client implementation:

class Client implements Invoker {
  invoke(options) {
    wrapper = loadWrapper() // plugin, wasm

    result = wrapper.invoke()

    if (result.error) {
      return { error: result.error };
    }
  
    if (result.encoded && !options.encode) {
      return { data: decode(result.data) };
    } else if (!result.encoded && options.encode) {
      return { data: encode(result.data) };
    } else {
      return { data: result.data };
    }
  }
}