patch 8.2.3750: error messages are everywhere

Problem:    Error messages are everywhere.
Solution:   Move more error messages to errors.h and adjust the names.
diff --git a/src/blob.c b/src/blob.c
index 2833c1a..0458571 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -209,7 +209,7 @@
     if (fwrite(blob->bv_ga.ga_data, 1, blob->bv_ga.ga_len, fd)
 						  < (size_t)blob->bv_ga.ga_len)
     {
-	emsg(_(e_write));
+	emsg(_(e_error_while_writing));
 	return FAIL;
     }
     return OK;