Add support for compile_commands.json

[rtbo]

Now that compile_commands.json is (at least partially) supported in serve-d (CCDB component in workspace-d), is it possible to add support for it in code-d?

What would be the TODO list to have this compilation database supported by code-d?

[WebFreak001]

what exactly do you need to have supported? / what's not working with the latest nightly / pre-release?

[rtbo]

I have a project that has a build/compile_commands.json file and not using dub. I'd like code-d to use that file for linting/imports etc. (path should be specified with an option as there can be multiple ones: build-dmd-release/compile_commands.json, build-ldc-debug/compile_commands.json ...) If this is supposed to work I don't see it. Code-d could even run the compile command when the corresponding file is open in order to scan for errors.