C++20 version of upcoming C++23 std::expected#239

Merged

2 commits merged intonv-morpheus:branch-23.01from ryanolson:std23_expected

Dec 7, 2022

+1,491-50

Commits on Dec 2, 2022

embedding the expected.hpp file from https://github.com/RishabhRD/expected ; replacing tl::expected
ryanolson
committed

Commits on Dec 7, 2022

updating to conform to contributing guidelines
ryanolson
committed