patch 8.0.0210: no support for bracketed paste

Problem:    Vim does not support bracketed paste, as implemented by xterm and
            other terminals.
Solution:   Add t_BE, t_BD, t_PS and t_PE.
diff --git a/src/vim.h b/src/vim.h
index 3273409..4ebf348 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2108,6 +2108,14 @@
     ASSERT_OTHER
 } assert_type_T;
 
+/* Mode for bracketed_paste(). */
+typedef enum {
+    PASTE_INSERT,	/* insert mode */
+    PASTE_CMDLINE,	/* command line */
+    PASTE_EX,		/* ex mode line */
+    PASTE_ONE_CHAR	/* return first character */
+} paste_mode_T;
+
 #include "ex_cmds.h"	    /* Ex command defines */
 #include "spell.h"	    /* spell checking stuff */