Introduce /redraw command

`/redraw` command allows resolve problem for usual users,
as well as developers.

Incredibly useful when debugging with something that
can trash out the output, like GDB.

Not to mention many asynchronous commands that can break the UI
at any point.

src/command/cmd_defs.c

@@ -2729,6 +2729,18 @@ static const struct cmd_t command_defs[] = {
               "/privacy logging off",
               "/privacy os off")
     },
+
+    { CMD_PREAMBLE("/redraw",
+                   parse_args, 0, 0, NULL)
+      CMD_MAINFUNC(cmd_redraw)
+      CMD_TAGS(
+              CMD_TAG_UI)
+      CMD_SYN(
+              "/redraw")
+      CMD_DESC(
+              "Redraw user interface. Can be used when some other program interrupted profanity or wrote to the same terminal and the interface looks \"broken\"." )
+    },
+
     // NEXT-COMMAND (search helper)
 };