chore: Contact import improvements (CW-1362) (#6747)

Fixes: https://linear.app/chatwoot/issue/CW-1362/csv-imports-are-not-working-properly
Fixes: #3462

---------

Co-authored-by: Sojan <sojan@pepalo.com>

spec/support/csv_spec_helpers.rb

@@ -0,0 +1,18 @@
+module CsvSpecHelpers
+  # Generates a Rack::Test::UploadedFile object from an array of arrays
+  # data: Accepts an array of arrays as the only argument
+  def generate_csv_file(data)
+    # Create a temporary file
+    temp_file = Tempfile.new(['data', '.csv'])
+
+    # Write the array of arrays to the temporary file as CSV
+    CSV.open(temp_file.path, 'wb') do |csv|
+      data.each do |row|
+        csv << row
+      end
+    end
+
+    # Create and return a Rack::Test::UploadedFile object
+    Rack::Test::UploadedFile.new(temp_file.path, 'text/csv')
+  end
+end