Decoding into a std::byte output iterator was not working because the
`*out++ = val` assignment doesn't work when the output is std::byte and
val is a char/unsigned char/uint8_t. Instead we need to explicitly
cast, but figuring out what we have to cast to is a little bit tricky.
This PR makes it work (and bumps the version for this and the is_hex
fix).
Previously you could only generate a string from a string_view, or could
manage the string yourself and pass input iterators plus an output
iterator.
This commit adds an intermediate version that creates a string from a
pair of input iterators.
Removes lokimq::string_view (the type alias is still provided for
backwards compat, but now is always std::string_view).
Bump version (on dev branch) to 1.2.0