[Possible bug] Require boost json module in the root CMakeLists

[AndreyMlashkin]

Describe the bug
If I use a boost package installed by apt-get, it would not contain json module and it will fail during compilation with an error

[ 37%] Building CXX object bin/assigner/CMakeFiles/assigner.dir/src/main.cpp.o
/home/andrei/nil/zkLLVM/bin/assigner/src/main.cpp:30:10: fatal error: boost/json/src.hpp: No such file or directory
   30 | #include <boost/json/src.hpp>
      |          ^~~~~~~~~~~~~~~~~~~~
compilation terminated.

To Reproduce
How to reproduce the behavior:

1. Install boost from ubuntu 22.04
2. Compile the project according to documentation

Expected behavior
A diagnostic error message on the first cmake run