Rename Block to RubyBlock at Ruby level

The parser presents the whole call that defines the block as a block. And so does the Ruby layer, as we don't want to do processing in ast.
Just making it clearer, also Vool:: block will have to be renamed

test/rubyx/parfait/test_object.rb

@@ -2,7 +2,7 @@ require_relative "helper"
 
 module RubyX
 
-  class TestObjecCompile < MiniTest::Test
+  class TestObjectCompile < MiniTest::Test
     include ParfaitHelper
     def source
       load_parfait(:object)