[ui, helios] Toast Component

[philrenaud]

Adds toast component styles from Helios to the Nomad Web UI

Resolves #16095

[github-actions]

Ember Asset Size action

As of f78f14d

Files that got Bigger 🚨:

File	raw	gzip
nomad-ui.js	+241 B	+30 B

Files that got Smaller 🎉:

File	raw	gzip
nomad-ui.css	-966 B	-207 B

Files that stayed the same size 🤷‍:

File	raw	gzip
vendor.js	0 B	0 B
vendor.css	0 B	0 B

[github-actions]

Ember Test Audit comparison

	main	f78f14d	change
passes	1467	1467	0
failures	0	0	0
flaky	0	0	0
duration	10m 53s 212ms	10m 54s 128ms	+916ms

[ChaiWithJai]

Could we use this as a chance to update flashMessages? I've always been annoyed with the API and how verbose we need to be when using it. This is could be a great opportunity to make a simple method on the service like:

showMessage(type, config) {
  this.flashMessages.add({
    color: type,
    destroyOnClick: false,
    timeout: 5000,
    ...config
  })
}

This would save ~10 lines of code every time we use this in the application.