Remove support for mod.json dependency array syntax

[Fleeym]

This also allows either object / string syntax for individual dependencies.

Here's how the new syntax will look like:

"dependencies": {
  "geode.node-ids": ">=2.0.0",
  "geode.custom-keybinds": {
    "version": ">=2.0.0",
    "importance": "required",
    "platforms": ["win", "mac"]
  }
}

Currently in v4, having string syntax is unsupported when using the object "dependencies" syntax, this PR also adds support for that, so that for example the geode.node-ids dependency above is valid.