Make it easier to migrate data to new server

[fmcpherson]

Is your feature request related to a problem? Please describe.
Right now to migrate Monica data to a new server one needs to know how to use mysql tools to manually import data from a export file, which can be generated, and that is an issue for people who are not proficient in mysql.

Describe the solution you'd like
Ideally there is an Import option within Monica that can read data from the export function to re-populate the database.

Describe alternatives you've considered (optional)
An external script or even clearly written instructions (for NOOBS) may be sufficient.

Additional context
I've been running the Dockerized version of Monica that that includes the monica container and uses the "default" mysql container and I have been able to do so with little or no knowledge of mysql. However, the latest release of Monica includes a new docker-compose.yml file and I am hesitant to pull the latest image. I am thinking building a new instance on a new server (that will ultimately replace what I have) may be a safer approach and hence my interest in export and import.