🚀: Create `Reducer` DSL with per-intent handling and config options

[Nek-12]

Description

We could achieve a nice intent handler DSL by building a FlowMVI plugin to replace reduce with a more robust handler, and additionally, give users an easier way to split their reducers apart (even though that'd make it less safe).

Example:

reducer {
   on<CounterIntent.Increment> {
        distinct() // default equals, allow customizing, similar to compose remember
        filter { it.value > 2 }
        mode = Cancel // what happens when queue builds up
        handle {
           updateState { copy(counter = counter++) }
        } // consider requiring handler builder return type from this lambda
   }
}

Requirements:

• Per-intent configuration available (e.g. drop latest on one, serialize on another intent)
  On new intent options:
• drop new
• cancel old
• await
• parallel
• per-intent catch blocks (opt?)
• filter/debounce/distinctUntilChanged for intents per-intent