Create a simple to use production ready Docker image

[PhilReinking]

With this PR we introduce the creation of Docker images for our releases. Unlike the local developer setup, this image is easy to install and has no Docker Compose dependencies.

The image uses a local SQLite database for storage. It also does use the local file storage for session and cache. If required the image can be configured to use a MySQL database, Redis for Cache & Session, and Minio for file uploads.

• [x] Create Dockerfile for production image
• [ ] Update Readme with instructions
• [x] Create Github Action for automatic image builds

[PhilReinking]

In this PR I removed the function to verify users since in a self hosted environment that is not expected to be a requirement. This must be added in the hosted version of Input.