This PR updates the ember/template-no-invalid-link-text rule to work correctly for conditional child content.

For example, the following template is valid, but currently fails lint for having empty link content.

<template>
  <a href="/play">{{#if game.inProgress}}Continue{{else}}Start{{/if}}</a>
</template>

The problem was occurring because the rule did not treat GlimmerBlockStatement nodes (like {{#if condition}}...{{/if}}) inside the link as dynamic content. Instead, it would skip them, effectively seeing the link text as empty when it only contained a block statement.

I updated the getTextContentResult function to flag GlimmerBlockStatement as dynamic, which bypasses the strict empty link check and allows the rule to gracefully ignore dynamic conditional contents.

I added a few additional tests (like the one above) that fail before this fix.