fix(terminal): stack overflow when too many csi args (#34012)

fix: stack overflow when too many csi args

Problem:
Crash when csi contains > 16 args. It's easy to trigger
when you attempt to pipe external terminal scrollback buffer.
```sh
nvim --clean --cmd "term printf
'\e[38:2:59:66:97;48:2:36:40:59;58:2:224:175:104;4:3m'"
```

Solution:
Increase buffer size.

src/nvim/vterm/vterm_internal_defs.h

@@ -15,7 +15,7 @@
 
 #define INTERMED_MAX 16
 
-#define CSI_ARGS_MAX 16
+#define CSI_ARGS_MAX 32
 #define CSI_LEADER_MAX 16
 
 #define BUFIDX_PRIMARY   0