Plugin configuration support

Add formal support for plugin configurations in the bsconfig.

Here's how it should work:

existing plugin string shorthand will still work

"plugins": [
    "./path/to/plugin.js",
    "plugin-from-node_modules"
]

plugin definitions can now be objects, with the following properties

• src - the plugin string shorthand described above (an npm package name, or a path to a nodejs script)
• config - the plugin-specific config object that will be given to the plugin, or a path to a jsonc config file to be loaded

"plugins": [
    {
        "src": "./path-to-plugin.js"
        "config": {
            //plugin-specific config
         }
    }, 
    {
        "src": "plugin-from-node_modules",
        "config": "path/to/config.json"
    }
]      

Plugins are given their configurations in a new lifecycle hook

This new configuration will be passed to the plugin in a new lifecycle hook (possibly called onSetConfiguration). Plugins may be reconfigured many times depending on whether watched files (such as bsconfig or specific plugin files) changed.

public onSetConfiguration(config: YourConfigInterfaceType) {
    this.config = config;
    //do stuff based on this config
}

Start by tracing bsconfig plugin loading and the existing plugin string shorthand, then review the proposed onSetConfiguration lifecycle hook and watched-file reconfiguration behavior. Done means supporting object plugin definitions with inline or JSONC config while preserving string shorthand and passing configuration to plugins through the new hook.