patch 8.2.0970: terminal properties are not available in Vim script

Problem:    Terminal properties are not available in Vim script.
Solution:   Add the terminalprops() function.
diff --git a/src/main.c b/src/main.c
index f686a5f..39e67e9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -407,6 +407,10 @@
     init_highlight(TRUE, FALSE); // set the default highlight groups
     TIME_MSG("init highlight");
 
+#if defined(FEAT_TERMRESPONSE)
+    init_term_props(TRUE);
+#endif
+
 #ifdef FEAT_EVAL
     // Set the break level after the terminal is initialized.
     debug_break_level = params.use_debug_break_level;