[LifetimeSafety] Detect invalidation of containers as fields

https://godbolt.org/z/Ye7o9xqff

```cpp
struct InvalidateMemberFields {
InvalidateMemberFields();

void invalidateField() {
auto it = container.begin();
container.push_back("1");
(void)*it;
}
void invalidateFieldRef() {
auto it = contiainerRef.begin();
contiainerRef.push_back("1");
(void)*it;
}

private:
std::vector container;
std::vector& contiainerRef;
};
```

Start with the linked Compiler Explorer reproducer and the LifetimeSafety implementation in LLVM. Check how invalidation is handled for the direct std::vector field and the referenced container, then establish tests showing that dereferencing the iterator after push_back is detected for both cases.

Written by the indexing model from the issue text.