Fix problem with substring in large message getting incorrectly reversed

OTP-11871
Fix problem with send printout not being tagged with connection name
Fix problem with comments getting lost when running parallel test cases

OTP-11898
Merge remote branch 'origin/peppe/common_test/telnet_reversed_strings' into maint

* origin/peppe/common_test/telnet_reversed_strings:
  Fix problem with send printout not being tagged with connection name
  Fix problem with substring in large message getting incorrectly reversed

OTP-11871
Merge remote branch 'origin/peppe/common_test/ct_comment_problem' into maint

* origin/peppe/common_test/ct_comment_problem:
  Fix problem with comments getting lost when running parallel test cases