Use a button instead of a link to block users

We're continuing to replace links with buttons, for the reasons
explained in commit 5311daadf.

We're also adding an ARIA label since on the same page there might be
several links to block different users.

app/views/moderation/users/index.html.erb

@@ -17,8 +17,14 @@
           <% if user.hidden? %>
             <%= t("moderation.users.index.hidden") %>
           <% else %>
-            <%= link_to t("moderation.users.index.hide"), hide_in_moderation_screen_moderation_user_path(user, request.query_parameters),
+            <%= render Admin::ActionComponent.new(
-                        method: :put, class: "button hollow alert" %>
+              :hide_in_moderation_screen,
+              user,
+              text: t("moderation.users.index.hide"),
+              method: :put,
+              "aria-label": true,
+              class: "button hollow alert"
+            ) %>
           <% end %>
         </td>
       </tr>

spec/system/admin/activity_spec.rb

@@ -239,7 +239,7 @@ describe "Admin activity" do
       visit moderation_users_path(search: user.username)
 
       within("#moderation_users") do
-        click_link "Block"
+        click_button "Block"
       end
 
       visit admin_activity_path

spec/system/moderation/budget_investments_spec.rb

@@ -75,7 +75,7 @@ describe "Moderate budget investments" do
           click_button "Search"
 
           within "tr", text: investment.author.name do
-            expect(page).to have_link "Block"
+            expect(page).to have_button "Block"
           end
         end
 

spec/system/moderation/comments_spec.rb

@@ -95,7 +95,7 @@ describe "Moderate comments" do
           click_button "Search"
 
           within "tr", text: comment.user.name do
-            expect(page).to have_link "Block"
+            expect(page).to have_button "Block"
           end
         end
 

spec/system/moderation/debates_spec.rb

@@ -66,7 +66,7 @@ describe "Moderate debates" do
           click_button "Search"
 
           within "tr", text: debate.author.name do
-            expect(page).to have_link "Block"
+            expect(page).to have_button "Block"
           end
         end
 

spec/system/moderation/proposal_notifications_spec.rb

@@ -70,7 +70,7 @@ describe "Moderate proposal notifications" do
           click_button "Search"
 
           within "tr", text: proposal_notification.author.name do
-            expect(page).to have_link "Block"
+            expect(page).to have_button "Block"
           end
         end
 

spec/system/moderation/proposals_spec.rb

@@ -65,7 +65,7 @@ describe "Moderate proposals" do
           click_button "Search"
 
           within "tr", text: proposal.author.name do
-            expect(page).to have_link "Block"
+            expect(page).to have_button "Block"
           end
         end
 

spec/system/moderation/users_spec.rb

@@ -64,7 +64,7 @@ describe "Moderate users" do
     within("#moderation_users") do
       expect(page).to have_content citizen.name
       expect(page).not_to have_content "Blocked"
-      click_link "Block"
+      click_button "Block"
     end
 
     within("#moderation_users") do