add 1D_UNet_for_FCS notebook, reqs, and version

[aseltmann]

Dear ZeroCostDL4Mic-Team,
After mailing with Esti this summer about contributing a 1D U-Net notebook, I finally came around to finish the notebook and create the pull request. As Esti requested, I added the notebook under Beta notebooks. I saw that you simplified the requirements.txt files, but I left it as it is produced from the notebook for now.

Some special implementations in this notebook which might not be found in the other U-Net notebooks:

• download helper for published connected datasets (published simulations for train, test, and validation, published applied data for model application, published models)
• in-notebook simulation of training, testing, and validation data
• model tracking and loading via mlflow
• improved PDF reports for training and evaluation
• FCS-specific functionality (section 6) with implementations of the correction functions from our connected preprint

Please let me know what you think - I am happy to receive your feedback!