`Logger`: Add a config `Dispatcher`

[nexushoratio]

We would like to have the ability to detect config changes so that we can save them.

• Define API
• Implement

[nexushoratio]

API:

Simple Dispatcher that takes the following events:

• new logger (data: logger name)
• new group (data: logger name, group name)
• used (data: logger name, group name)

This may actually be difficult as groups seem to have know knowledge of the associated logger. Not sure how fancy a DefaultMap factory can be.

---

Actually, DefaultMap.get() is enhanced precisely for such situations, and it used to configure the default mode for Logger's groups.

Requires:

• constructor take an arg and do something with it:
  

  userscripts/lib/base.js

  Lines 1174 to 1175 in 5eb580f

  	/** @param {Logger.#GroupMode} mode - Initial mode for this group. */
  	constructor(mode) {

• factory function takes an argument and passes it in:
  

  userscripts/lib/base.js

  Line 1167 in 5eb580f

  #groups = new DefaultMap(x => new Logger.#Group(x));

• get passes in an extra param:
  

  userscripts/lib/base.js

  Line 1105 in 5eb580f

  return this.#groups.get(sanitizedName, defaultMode);