wil::reg::set_value doesn't work with std::wstring values

When you try to call wil::reg::set_value with an std::wstring argument you get a compiler error.

e.g.:

std::wstring my_value = L"Hello";
wil::reg::set_value(HKEY_CURRENT_USER, L"Software\\MyApp", L"MyValue", my_value);

results in:

static_assert failed: 'Unsupported type for set_value_type'

The issue seems to be that reg_view_t::set_value deduces the argument type as const R& value, which will always be the non-const version:

https://github.com/microsoft/wil/blob/3ecba603d9789435b0661be7b7154d45c195ef98/include/wil/registry_helpers.h#L1182-L1187

It then passes R to reg_value_type_info::set_value_type<R>, but this expects the const version:

https://github.com/microsoft/wil/blob/3ecba603d9789435b0661be7b7154d45c195ef98/include/wil/registry_helpers.h#L1008-L1012

This probably means that all other smart string variants listed there are also affected.

I think the best approach to fix this would be to switch all the affected set_value_type specializations to non-const.

Start in include/wil/registry_helpers.h, especially reg_view_t::set_value around lines 1182-1187 and the reg_value_type_info::set_value_type specializations around lines 1008-1012. Reproduce the shown std::wstring example, then verify that it and the other listed smart string variants are accepted without the unsupported-type compiler error.