Reorganize SDG tag list components

So now we've got a component receiving records (goals or targets) and a
related model (Debate, Proposal, ...), with optionally a link to see
more tags.

This way we simplify some logic since the `TagList` classes were dealing
with too many cases (a record is passed, a class name is passed, a limit
is passed), ... Now `TagList` only deal with the natural `TagList` case,
which is listing the tags for a record. The case where a class name is
passed is used in the `TagCloud` class.

spec/components/sdg/goals/tag_cloud_component_spec.rb

@@ -15,11 +15,13 @@ describe SDG::Goals::TagCloudComponent, type: :component do
     expect(page).to have_content "Filters by SDG"
   end
 
-  it "renders all goals" do
+  it "renders all goals ordered by code" do
     component = SDG::Goals::TagCloudComponent.new("Proposal")
 
     render_inline component
 
-    expect(page).to have_css ".sdg-goal-icon", count: 17
+    expect(page).to have_selector ".sdg-goal-icon", count: 17
+    expect(page.first("a")[:title]).to end_with "goal 1"
+    expect(page.all("a").last[:title]).to end_with "goal 17"
   end
 end

spec/components/sdg/goals/tag_list_component_spec.rb

@@ -60,16 +60,4 @@ describe SDG::Goals::TagListComponent, type: :component do
                               title: "One more goal",
                               href: "/debates/#{debate.to_param}"
   end
-
-  context "given a class name" do
-    let(:component) { SDG::Goals::TagListComponent.new("Debate") }
-
-    it "renders all goals ordered by code" do
-      render_inline component
-
-      expect(page).to have_selector "li", count: 17
-      expect(page.first("a")[:title]).to end_with "goal 1"
-      expect(page.all("a").last[:title]).to end_with "goal 17"
-    end
-  end
 end