Make schedule method asynchronous to handle Promise callbacks

[thinhbuzz]

refer to commit d5f7dff

[thinhbuzz]

Old

const value = await Il2Cpp.mainThread.schedule<number>(() => {
    return new Promise<number>(resolve => resolve(1));
});
// Error: TS2345: Argument of type () => Promise<number> is not assignable to parameter of type () => number

New

const value = await Il2Cpp.mainThread.schedule<number>(() => {
    return new Promise<number>(resolve => resolve(1));
});
// OK

[vfsfitvnm]

Hmm, schedule should not be async, but should handle Promises as well. What's your use case?