[clang-tidy] Check bugprone-unchecked-optional-access triggers a false-positive related to std::reference_wrapper

This code triggers a false-positive result from clang-tidy check bugprone-unchecked-optional-access (see https://godbolt.org/z/PEY3Ebrzj):

```c++
#include
#include
#include

struct Group
{
int m_id;
};

struct KeyBase
{
std::optional m_group;
};

struct KeyWrapper
{
const KeyBase& m_keyBase;
};

using KeyWrappers = std::list>;

void check(const KeyWrappers& items)
{
for (const KeyWrapper& item : items)
{
if (item.m_keyBase.m_group.has_value())
{
const Group& g = item.m_keyBase.m_group.value(); // <-- false positive
}
}
}
```

The issue occurs on the main branch (upcoming clang 23) but is present at least since clang 21.

Could be related to #203686 but I am not sure.

Reproduce the false positive with the provided std::reference_wrapper example using the bugprone-unchecked-optional-access check, starting from the Godbolt link and the check's implementation. Trace how the range item is modeled, then add a regression test showing that the guarded optional access produces no diagnostic.

Written by the indexing model from the issue text.