[Feature] Environment variables should take precedence over the configuration file

[dannyhpy]

Description

This would be really useful for Docker users.
Currently, when you to change a specific setting, you need to edit the configuration file.

It would be more convenient to have the ability to change a setting from the command line especially for testing purposes (or from the docker-compose.yml file for Docker users)

For instance, this would allows you to change the domain pretty easily if you have a Raspberry Pi and want to move it temporary to an another location without having to change the config file.

SSH_DOMAIN=176.173.39.149 gitea web

(I don't think this is similar to any issue out there, but there are a lot of issues so if there is already an issue mentioning this, I'm sorry about that)

[techknowlogick]

Closing as dupe of #10123

[zeripath]

There is a contrib command environment-from-ini