patch 8.2.1108: mouse left-right scroll is not supported in terminal window

Problem:    Mouse left-right scroll is not supported in terminal window.
Solution:   Implement mouse codes 6 and 7. (Trygve Aaberge, closes #6363)
diff --git a/src/terminal.c b/src/terminal.c
index 5424574..bd5fd41 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -1389,8 +1389,8 @@
 
 	case K_MOUSEUP:		other = term_send_mouse(vterm, 5, 1); break;
 	case K_MOUSEDOWN:	other = term_send_mouse(vterm, 4, 1); break;
-	case K_MOUSELEFT:	/* TODO */ return 0;
-	case K_MOUSERIGHT:	/* TODO */ return 0;
+	case K_MOUSELEFT:	other = term_send_mouse(vterm, 7, 1); break;
+	case K_MOUSERIGHT:	other = term_send_mouse(vterm, 6, 1); break;
 
 	case K_LEFTMOUSE:
 	case K_LEFTMOUSE_NM:
@@ -2474,6 +2474,8 @@
 	restore_cursor = TRUE;
 
 	raw_c = term_vgetc();
+if (raw_c > 0)
+    ch_log(NULL, "terminal_loop() got %d", raw_c);
 	if (!term_use_loop_check(TRUE) || in_terminal_loop != curbuf->b_term)
 	{
 	    // Job finished while waiting for a character.  Push back the