The line breaks can be included in the literal strings, so you don't need to worry about which characters are used. You do have to put " ' + ' " in front of any GO however.

SELECT 'DROP PROCEDURE [' + SCHEMA_NAME([schema_id]) + '].[' + [name] + ']

' + 'GO

' + OBJECT_DEFINITION([object_id])+ '

' + 'GO'

FROM sys.objects

WHERE [name] = 'Test SP'