Functions that construct the database should check for errors

[MrMino]

TIL ~~that in my environment, if I install pyscope, the pyscope command is not available~~ pycscope != pyscope. This meant, that if I tried to create the database, the command in vim would show success, yet only .files file would be created.

It would be nice if a failure message would be shown instead of "yay, success" one :).

[devjoe]

@MrMino I got your point, thanks for your suggestion. I hope I will have time to tweak these two functions 😹:

function! codequery#db#make_db_callback(job, status) dict
    echom 'Done!  (' . self.db_path . ')'
endfunction

function! codequery#db#make_db_nvim_callback(job, data, status) dict
    echom 'Done! Built codequery db!'
endfunction```

If you can help, PR is welcome~

[MrMino]

I'd love to send a PR for this, but I'm not very well versed in developing in vimscript. We'll see.