P1097 Named character escapes

[jensmaurer]

P1097R2 Named character escapes (R. Martinho Fernandes)

[tahonermann]

This paper is ready for EWG. It received strong support in EWGI in San Diego (http://wiki.edg.com/bin/view/Wg21sandiego2018/P1097R1). Removing the SG16 label.

[davidstone]

This paper was discussed in EWG in Belfast. There was encouragement for further work in this area as a language feature, but we do not have consensus to adopt the feature for C++23 at this time.