emit custom life-cycle events

[leastbad]

Type of PR (feature, enhancement, bug fix, etc.)

Feature

Description

Adds custom events so that developers can choose to handle specific Reflex actions. Easier to explain with an example:

// today, we don't know which Reflex action this is for
document.addEventListener('stimulus-reflex:after', event => console.log(event))

// this PR makes it possible to know that it was for the `status` action
document.addEventListener('stimulus-reflex:after:status', event => console.log(event))

Why should this be added

Today, we emit events for Reflex actions in a generic way: https://docs.stimulusreflex.com/guide/lifecycle#life-cycle-events

Discussion with Lorenzo made me realize that we could easily have SR emit both generic and custom events: https://discordapp.com/channels/629472241427415060/733725826411135107/907294392946130985

Checklist

• My code follows the style guidelines of this project
• Checks (StandardRB & Prettier-Standard) are passing
• This is not a documentation update