Feature Request: Add the ability to clone an existing Factorio instance to the same worker node

[jbirch]

One of the most satisfying things about Clusterio is that when a given "problem" is solved, it can be packaged up as a Factorio save and scaled significantly further than any single map can reasonably handle. The mechanism for doing this right now is to:

• Download the save of the instance you'd like to duplicate (or save from in-game).
• Create a new instance.
• Assign the new instance.
• Manually duplicate any configuration changes like visibility, password, etc.
• Upload the save from the first step.

A simplification of this process could include "cloning" an existing instance to the same worker node, that worked similar to the following.

• A button to "clone" is added to the instance UI
• Clicking this button sends a command to make a save to the running instance
• An instance is created that is assigned to the same worker node, with the same configuration as the copied instance, with the save uploaded.

There's a couple of edge cases in configuration that I imagine shouldn't be exact clones. For example, the name should be modified by appending (clone) to the end or something. There's also some question in my mind about whether or not the save should happen, or just the last save should be taken - The instance size is effectively unbounded, so waiting for a save in the critical path is possibly annoyingly or prohibitively slow, unless the clone operation is some async op.