[csolution] Add reference to `compile_commands.json` file into `cbuild.yml`

[brondani]

It's known that compile_commands.json are stored alongside its related artifacts, i.e. in the context-depth output folder, however there is no explicit reference to it.

build:
  output:
    - type: compilation database
      file: compile_commands.json

Also consider adding a path node with output files and output-dirs already combined, for example:

build:
  output-dirs:
    outdir: ./custom
  output:
    - type: elf
      file: program.axf
      path: ./custom/program.axf
    - type: compilation database
      file: compile_commands.json
      path: ./custom/compile_commands.json

[ReinhardKeil]

@brondani thanks for that proposal. We need also to consider the compiler symbol export file (currently this is intermixed with .clangd). This file seems to be currently created by the VSCode extension, but is also required for static code analyzers and hence useful in CI context.

[brondani]

We need also to consider the compiler symbol export file

I believe this is tracked on #2228