Move recipe_name to TemplateHelper

- Updated app_spec.rb to check the generator context for recipe_name
- Updated cookbook_spec.rb to check the generator context for recipe_name
- Updated spec shared/a_file_generator.rb to check the generator context for recipe_name
- Added recipe_name to generator context in generator_commands/app.rb
- Added recipe_name to generator context in generator_commands/cookbook.rb
- Added recipe_name to generator context in generator_commands/cookbook_code_file.rb
- Removed variable insertion from app.rb recipe in skeleton cookbook
- Removed variable insertion from cookbook.rb recipe in skeleton cookbook
- Removed variable insertion from recipe.rb recipe in skeleton cookbook
- Updated recipe_spec.rb.erb template to use recipe_name from generator context
- Updated recipe.rb.erb template to use recipe_name from generator context