patch 8.2.0936: some terminals misinterpret the code for getting cursor style

Problem:    Some terminals misinterpret the code for getting cursor style.
Solution:   Send a sequence to the terminal and check the result. (IWAMOTO
            Kouichi, closes #2126)  Merged with current code.

src/main.c

@@ -793,7 +793,7 @@ vim_main2(void)
 
 #if defined(FEAT_TERMRESPONSE)
     // Must be done before redrawing, puts a few characters on the screen.
-    may_req_ambiguous_char_width();
+    check_terminal_behavior();
 #endif
 
     RedrawingDisabled = 0;