Fix server error log messages:

  In MSR, There shall be error messages per channel in the server log, clearly
  specifying the channel name.This would make debugging/tracing easy.

   So, in this patch following are done:
   1) Reserve two for_channel_str and for_channel_uppercase_str in Master_info
        class to use them in error messages.
   2) To reduce memory, we save it in Master_info rather than in Slave_reporting
        Capability
   3) Use virutal functions in Master_info, Relay_log_info and Slave_Worker_info
       to call get_for_channel_str() to get error messages per channel.

   4) For rli_fake, just return the empty string.

   5) Added 'for channel' suppressions in the test file and updated result files.