Add ability to invoke Commands with a Stimulus controller

[hopsoft]

This PR is exploratory, but may prove quite powerful and convenient. It introduces a new optional Stimulus controller that can be used to invoke commands in addition to event delegation. Note that event delegation is still used under the hood.

Trigger a command based on an explicit Stimulus controller.

<a href="#" 
  data-controller="command" 
  data-action="click->command#invoke:capture"
  data-command-name-value="MyCommand#perform">
  Trigger a TurboBoost Command
</a>

Submit a form and invoke a command at the same time. All form params will be available to the controller and command server side. Note that this will perform a real form submit... not shenanigans to approximate one.

<form id="my-form">
  ...
</form>

<a href="#" 
  data-controller="command" 
  data-action="click->command#invoke:capture"
  data-command-form-value="my-form"
  data-command-name-value="MyCommand#perform">
  Submit the form and Trigger a TurboBoost Command
</a>

I believe this will satisfy the requested feature from #83

[hopsoft]

We may need to remove capture from the event delegation for this to work reliably. 🤔

---

On second thought, I don't think this will be necessary.

[julianrubisch]

My initial thought looking at this: Let's add a helper that writes that markup for you?

[hopsoft]

Note

Related to #83, Hopefully I can get some time to refocus on this effort soon. 🤞🏻