chore: dont copy body

feat: set header fields in response

fix: add missing fstream header include

This is required to build expresscpp with GCC11+

Signed-off-by: Pascal Bach <pascal.bach@siemens.com>

chore: simply make it dependent on boost

fix: build issues with new C++ 20

0.20.0

0.19.3

0.19.2

0.19.1

0.19.0