Linter: Implement erb-no-conditional-html-element rule

[marcoroth]

This pull request adds a new linter rule erb-no-conditional-html-element which disallows the use of HTMLConditionalElementNode in templates.

The following snippet:

<% if @with_icon %>
  <div class="icon">
<% end %>

  <span>Content</span>

<% if @with_icon %>
  </div>
<% end %>

Now fails with:

Avoid opening and closing `<div>` tags in separate conditional blocks with the same condition. This pattern is difficult to read and maintain. Consider using a `capture` block instead: <% content = capture do %> ... your content here ... <% end %> <%= @with_icon ? content_tag(:div, content) : content %>

This is a follow up on #1146 as it introduced the new HTMLConditionalElementNode.

[pkg-pr-new]

npx https://pkg.pr.new/@herb-tools/formatter@1150

npx https://pkg.pr.new/@herb-tools/language-server@1150

npx https://pkg.pr.new/@herb-tools/linter@1150

commit: f8765a5

[github-actions]

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