[clang-tidy] extend readability-redundant-member-init to non-static data member initializers

~~~cpp
#include <vector>
struct S {
    S() : x() {}
    std::vector<int> v{};
    std::vector<int> w = {};
    std::vector<int> x;
};
~~~
~~~console
<[source>:3:11: warning: initializer for member 'x' is redundant [readability-redundant-member-init]
    S() : x() {}
          ^~~~
~~~
It would be nice to get warnings also for `v` and `w`.
https://godbolt.org/z/P9KaeW485