runtest --stop pause stops before terminating the redis server (#7513)

in the majority of the cases (on this rarely used feature) we want to
stop and be able to connect to the shard with redis-cli.
since these are two different processes interracting with the tty we
need to stop both, and we'll have to hit enter twice, but it's not that
bad considering it is rarely used.

(cherry picked from commit 02ef355f98691adba4126bbdab0d4d2bfe475701)

tests/support/test.tcl

@@ -153,6 +153,12 @@ proc test {name code {okpattern undefined}} {
 
             incr ::num_failed
             send_data_packet $::test_server_fd err [join $details "\n"]
+
+            if {$::stop_on_failure} {
+                puts "Test error (last server port:[srv port], log:[srv stdout]), press enter to teardown the test."
+                flush stdout
+                gets stdin
+            }
         } else {
             # Re-raise, let handler up the stack take care of this.
             error $error $::errorInfo

tests/test_helper.tcl

@@ -360,7 +360,7 @@ proc read_from_test_client fd {
         lappend ::failed_tests $err
         set ::active_clients_task($fd) "(ERR) $data"
         if {$::stop_on_failure} {
-            puts -nonewline "(Test stopped, press enter to continue)"
+            puts -nonewline "(Test stopped, press enter to resume the tests)"
             flush stdout
             gets stdin
         }