This commit does the following:
- creates a new cpp/ql/lib folder and moves the majority of `.qll` files
from C++ into it.
- updates references to these files from the relevant `.ql` files.
- updates and adds `qlpack.yml` files to create publishable qlpacks
for cpp.
- updates the ``misc/suite-helpers/qlpack.yml` file to make it
publishable
- adds qlpack.lock.yml files for each published pack.
