runtime(vim): Update base syntax, match :debug and :break* commands

Match full :debug, :breakadd, :breakdel and :breaklist commands.

closes: #18748

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/syntax/testdir/input/vim_ex_debug.vim

@@ -0,0 +1,13 @@
+" Vim :debug command
+
+
+debug echo "..."
+
+function Foo()
+  debug echo "..."
+endfunction
+
+def Bar()
+  debug echo "..."
+enddef
+