Skip extract_hyperlinks if not required

Revisiting #436 .

This Patch uses relationships data to determine if a sheet includes hyperlinks or not.

As extract_hyperlinks loads the whole document in memory it is quite problematic for each_row_streaming. This patch tries to skip extract_hyperlinks when not required.

lib/roo/excelx/relationships.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'roo/excelx/extractor'
 
 module Roo
@@ -11,10 +13,16 @@ def to_a
         @relationships ||= extract_relationships
       end
 
+      def include_type?(type)
+        to_a.any? do |_, rel|
+          rel["Type"]&.include? type
+        end
+      end
+
       private
 
       def extract_relationships
-        return [] unless doc_exists?
+        return {} unless doc_exists?
 
         doc.xpath('/Relationships/Relationship').each_with_object({}) do |rel, hash|
           hash[rel['Id']] = rel

lib/roo/excelx/sheet_doc.rb

@@ -22,7 +22,7 @@ def cells(relationships)
 
       def hyperlinks(relationships)
         # If you're sure you're not going to need this hyperlinks you can discard it
-        @hyperlinks ||= if @options[:no_hyperlinks]
+        @hyperlinks ||= if @options[:no_hyperlinks] || !relationships.include_type?("hyperlink")
           {}
         else
           extract_hyperlinks(relationships)