Respect user preferred dir and allow to configure logs dir

[krassowski]

This PR:

• fixes Should allow to configure location of /generate error logs #487
• fixes /generate should write to --preferred-dir or current dir, nor --root-dir #488

[3coins]

@krassowski
Thanks for working on this change. I have one comment about the logs dir name, looks good otherwise.

[JasonWeill]

@krassowski Thanks for your patience on this PR! Could you please rebase this change against main?

[krassowski]

Done @JasonWeill

[3coins]

@krassowski
Thanks for making the updates. LGTM!

[krassowski]

Thank you both!

[dlqqq]

@meeseeksdev please backport to 1.x

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout 1.x
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 976f8b9303d198fb339f7b594d29e4cd879618a4

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #490: Respect user preferred dir and allow to configure logs dir'

4. Push to a named branch:

git push YOURFORK 1.x:auto-backport-of-pr-490-on-1.x

5. Create a PR against branch 1.x, I would have named this PR:

"Backport PR #490 on branch 1.x (Respect user preferred dir and allow to configure logs dir)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.