Update to Dockerfile to install plugins dependencies and addition of Singularity.def file

[DimitriosBellos]

Hi Neville,

In this pull request, I update the Dockerfile to install the ctffind and IMOD since they are plugin dependencies.
For MotionCorr2 in order to install you have to apply to a form (not able to download using the command line). For docker to install it, we might have to download it beforehand and add it in the Ot2Rec repo.
I also changed the base from nvidia/cuda:11.4-devel-ubuntu20.04 to nvidia/cuda:10.1-devel-ubuntu18.04 (nvidia/cuda:10.1-devel-ubuntu20.04 does not exist as CUDA 10.1 is not build for Ubuntu 20.04) because IMOD 4.11 (recent version) is only compatible with CUDA 10 or lower. The installed python is still 3.8. I could had Dockerfile to install IMOD from source, but the most recent open source version that they have available is 4.0.26

I also added Singularity.def file (its the equivalent of Dockerfile for Singularity).
You can easily create a singularity container (Ot2Rec.sif) by running sudo singularity build Ot2Rec.sif Singularity.def
Like docker you can push the singularity containers to cloud.sylabs.io

[DimitriosBellos]

I have edited the Dockerfile to install all necessary software for the plugins that can be available publicly (I think for all of them). These are IMOD, Savu, RedLionfishDeconv, ctffind

I removed the Singularity.def file since Joss told me that if users want singularity containers they can build them by pulling the docker containers from quay.io . I include it here in case you want to have it.

I am planning of pushing the docker container I made in the ot2rec repo in quay.io by the end of today under the tag ot2rec:latest_plus_plugin_dependencies . Let me know if you do not want me not to do this and if you want to review the pull request first, merge it with main, build the docker container yourself and push it to the ot2rec repo yourself

The Singularity.def is within the zip file. You can use it to build the singularity container without having to build it from an existing docker container the quay.io
Singularity.zip