patch 8.0.0231: bracketed paste mode is not tested

Problem:    There are no tests for bracketed paste mode.
Solution:   Add a test.  Fix repeating with "normal .".

src/testdir/test_paste.vim

@@ -0,0 +1,41 @@
+" Tests for bracketed paste.
+
+" Bracketed paste only works with "xterm".
+set term=xterm
+
+func Test_paste_normal_mode()
+  new
+  call setline(1, ['a', 'b', 'c'])
+  2
+  call feedkeys("\<Esc>[200~foo\<CR>bar\<Esc>[201~", 'xt')
+  call assert_equal('bfoo', getline(2))
+  call assert_equal('bar', getline(3))
+  call assert_equal('c', getline(4))
+
+  normal .
+  call assert_equal('barfoo', getline(3))
+  call assert_equal('bar', getline(4))
+  call assert_equal('c', getline(5))
+  bwipe!
+endfunc
+
+func Test_paste_insert_mode()
+  new
+  call setline(1, ['a', 'b', 'c'])
+  2
+  call feedkeys("i\<Esc>[200~foo\<CR>bar\<Esc>[201~ done\<Esc>", 'xt')
+  call assert_equal('foo', getline(2))
+  call assert_equal('bar doneb', getline(3))
+  call assert_equal('c', getline(4))
+
+  normal .
+  call assert_equal('bar donfoo', getline(3))
+  call assert_equal('bar doneeb', getline(4))
+  call assert_equal('c', getline(5))
+  bwipe!
+endfunc
+
+func Test_paste_cmdline()
+  call feedkeys(":a\<Esc>[200~foo\<CR>bar\<Esc>[201~b\<Home>\"\<CR>", 'xt')
+  call assert_equal("\"afoo\<CR>barb", getreg(':'))
+endfunc