Fix pynput import error in RQD docker

[n-jay]

Link the Issue(s) this Pull Request is related to.
#1301

Summarize your change.
Building and running RQD on docker results in a ERROR:rqd.rqnimby:Failed to import pynput caused by ImportError: this platform is not supported.

This is caused by pynput expecting an X11 server for the GUI which docker does not have or require.
Further details referenced in the pynput platform limitations doc.

This was resolved via the following steps:

1. Amend rqconstants.py to accept USE_NIMBY_PYNPUT changes via rqd.conf
2. Update the RQD Dockerfile to setup rqd.conf configuration during setup as described here.

[bcipriano]

@DiegoTavares Any thoughts here? I think you have some experience with the nimby stuff.

The changes looks ok to me, at least as a stopgap.

[n-jay]

at least as a stopgap.

If I'm understanding correctly, if Nimby allows idle artist workstations to be used as RQD nodes, I was assuming that its capabilities would not be necessary for the Docker setup which will more likely be deployed in a headless environment like a cloud render farm.
Would a more permanent solution be removing/replacing Nimby or pynput altogether?

[DiegoTavares]

The nimby logic is set to try pynput and failover to nop if it's not installed and it logs if it had failed to nop.

I agree this PR is good to prevent an error from been printed when we know pynput is not available. But it would be good to confirm not having pynput is not actually returning an error because it shouldn't