FEATURE: Add invite link to the sidebar (#29448)

This commit adds a new "Invite" link to the sidebar for all users who can invite to the site. Clicking the link opens the invite modal without changing the current route the user is on. Admins can customize the new link or remove it entirely if they wish by editing the sidebar section.

Internal topic: t/129752.

db/migrate/20241025045928_add_invites_link_to_sidebar.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+class AddInvitesLinkToSidebar < ActiveRecord::Migration[7.1]
+  def up
+    community_section_id = DB.query_single(<<~SQL).first
+      SELECT id
+      FROM sidebar_sections
+      WHERE section_type = 0
+    SQL
+
+    return if !community_section_id
+
+    max_position = DB.query_single(<<~SQL, section_id: community_section_id).first
+      SELECT MAX(ssl.position)
+        FROM sidebar_urls su
+             JOIN sidebar_section_links ssl ON su.id = ssl.linkable_id
+       WHERE ssl.linkable_type = 'SidebarUrl'
+         AND ssl.sidebar_section_id = :section_id
+         AND su.segment = 0
+    SQL
+
+    updated_rows = DB.query_hash(<<~SQL, position: max_position, section_id: community_section_id)
+      DELETE FROM sidebar_section_links
+       WHERE position > :position
+         AND sidebar_section_id = :section_id
+         AND linkable_type = 'SidebarUrl'
+      RETURNING user_id, linkable_id, linkable_type, sidebar_section_id, position + 1 AS position, created_at, updated_at
+    SQL
+    updated_rows.each { |row| DB.exec(<<~SQL, **row.symbolize_keys) }
+        INSERT INTO sidebar_section_links
+        (user_id, linkable_id, linkable_type, sidebar_section_id, position, created_at, updated_at)
+        VALUES
+        (:user_id, :linkable_id, :linkable_type, :sidebar_section_id, :position, :created_at, :updated_at)
+      SQL
+
+    link_id = DB.query_single(<<~SQL).first
+      INSERT INTO sidebar_urls
+      (name, value, icon, external, segment, created_at, updated_at)
+      VALUES
+      ('Invite', '/new-invite', 'paper-plane', false, 0, now(), now())
+      RETURNING sidebar_urls.id
+    SQL
+
+    DB.exec(<<~SQL, link_id:, section_id: community_section_id, position: max_position + 1)
+      INSERT INTO sidebar_section_links
+      (user_id, linkable_id, linkable_type, sidebar_section_id, position, created_at, updated_at)
+      VALUES
+      (-1, :link_id, 'SidebarUrl', :section_id, :position, now(), now())
+    SQL
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end