patch 8.2.3985: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more error messages to errors.h.
diff --git a/src/term.c b/src/term.c
index 4757d85..b3df1b3 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2384,7 +2384,7 @@
 	    emsg(error_msg);
 	else
 #endif
-	    semsg(_("E436: No \"%s\" entry in termcap"), name);
+	    semsg(_(e_no_str_entry_in_termcap), name);
     }
     return FAIL;
 }
@@ -3161,7 +3161,7 @@
      * MUST have "cm": cursor motion.
      */
     if (*T_CM == NUL)
-	emsg(_("E437: terminal capability \"cm\" required"));
+	emsg(_(e_terminal_capability_cm_required));
 
     /*
      * if "cs" defined, use a scroll region, it's faster.