[breakchange] refact lazy local variable

[poor-circle]

Why

Now, the lazy local is a void*, which is dangerous, and user need manage life-time manually.

What is changing

Refact lazy local. Now we allow user add local variable derived from LazyLocalBaseImpl. we aslo support SimpleLazyLocal for simple local variable case.

Example

struct mylocal : public LazyLocalBaseImpl<mylocal> {
    mylocal(std::string name) : _name(std::move(name)) {}
    std::string& name() { return _name; }
    std::string _name;
};

Lazy<void> task() {
  // if no local or local type is not corret, return nullptr
  mylocal* local =co_await CurrentLazyLocals<mylocal>{};
  assert(base->name()=="Hello");
  local->name()="HI";

  // if no local variable, return nullptr
  LazyLocalBase* local =co_await CurrentLazyLocals{};
  assert(local->empty()==false);
}
// local-variable will life until callback finished. User dont need to manage it.
task().setLazyLocal<mylocal>("Hello"s).start([](auto&&){
});

The type check is very fast (only need compare a pointer). Dont need RTTI.