Extract rule: template-no-duplicate-id

[NullVoxPopuli]

Split from #2371.

[johanrd]

Claude Review: comparing against ember-template-lint no-duplicate-id

blockParams scoping causes false negatives. The PR pushes/pops a scope for elements with blockParams, isolating all IDs inside — including static ones. The original doesn't do element-level scoping.
This is missed:

<MyComponent as |foo|>
  <div id="shared-id"></div>
</MyComponent>
<div id="shared-id"></div>

"shared-id" is added inside the component scope, which gets popped on exit — so the second occurrence isn't detected. Remove the blockParams scope push/pop.

Block-param ID disambiguation is different. The original's getMustacheValue walks up to the yield block ancestor and appends tag + line + column to make block-param-derived IDs unique across different
component invocations (e.g. {{inputProperties.id}} in two separate <MyComponent> blocks). The PR uses sourceCode.getText() which returns identical strings for both → would be a false positive once the
scoping above is removed. resolveIdValue needs the same location-aware keying for paths whose head is a block param.

conditionalReportedDuplicates suppresses valid reports. Not in the original. When an outer-scope ID appears in multiple branches, the original reports each one:

<div id={{this.divId00}}></div>
{{#if this.foo}}                                                                                                                                                                                                   
  <div id={{this.divId00}}></div>   {{!-- both report --}}
{{else}}                                                                                                                                                                                                           
  <div id={{this.divId00}}></div>   {{!-- original reports, PR suppresses --}}
{{/if}}                                                                                                                                                                                                            

Original: 2 errors. PR: 1 error. Remove conditionalReportedDuplicates — the conditional stack already handles branch isolation.