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.
This one C++ test has its own `queries.xml` to make "outside-of-source" path filtering work, as detailed in commit 2550788598. I've replaced the `queries.xml` with `qlpack.yml`, added a comment, and added that pack to the `.codeqlmanifest.json` at the root of the repo. This will allow the library dependencies of this pack to be resolved without the need for a `--search-path` option with the upcoming packaging changes.
This entry in `.codeqlmanifest.json` was intended to allow
unpacking the CodeQL CLI as a subdirectory of `ql`, and things
would Just Work.
However, it is not necessary anymore because recent releases of
the CLI will search their own directory as a fallback
_independently_ of the parent directory.
On the contrary, removing this link will make internal testing
easier because you then run a test build of the CLI with
`--search-path` pointing to the `ql` checkout without inadvertently
making extractors in a _different_ build that is unpacked there visible.
