Extract rule: template-no-bare-yield

[NullVoxPopuli]

Split from #2371.

[johanrd]

Review from claude: comparing against ember-template-lint no-yield-only

⚠️Fundamentally different semantics. The original only flags templates whose entire content is a bare {{yield}} — nothing else (whitespace and comments excluded). It's about preventing wrapper components
that just pass through their block with no added value.

The PR flags any {{yield}} without parameters, regardless of what else is in the template. This is a much broader rule:

{{!-- Original: OK (yield is not the only content). PR: flagged --}}                                                                                                                                               
<div>{{yield}}</div>                                                                                                                                                                                             
                                                                                                                                                                                                                   
{{!-- Original: flagged (yield is the only content). PR: also flagged --}}                                                                                                                                       
{{yield}}