add nn-cli example (#4373)

an example application with flexible cli options which
aims to allow us to perform any wasi-nn operations.

eg.
```
--load-graph=file=fixture/model.xml,file=fixture/model.bin,id=graph
--init-execution-context=graph-id=graph,id=ctx
--set-input=file=fixture/tensor.bgr,context-id=ctx,dim=1,dim=3,dim=224,dim=224
--compute=context-id=ctx
--get-output=context-id=ctx,file=output.bin
```

wamr-wasi-extensions/samples/nn-cli/map.c

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2025 Midokura Japan KK.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "map.h"
+
+static uintmax_t *
+map_find_slot(struct map *m, const char *name)
+{
+    size_t i;
+    for (i = 0; i < m->nentries; i++) {
+        if (!strcmp(m->entries[i].k, name)) {
+            return &m->entries[i].v;
+        }
+    }
+    return NULL;
+}
+
+static void
+map_append(struct map *m, const char *k, uintmax_t v)
+{
+    m->entries = realloc(m->entries, (m->nentries + 1) * sizeof(*m->entries));
+    if (m->entries == NULL) {
+        exit(1);
+    }
+    struct map_entry *e = &m->entries[m->nentries++];
+    e->k = k;
+    e->v = v;
+}
+
+void
+map_set(struct map *m, const char *k, uintmax_t v)
+{
+    uintmax_t *p = map_find_slot(m, k);
+    if (p != NULL) {
+        fprintf(stderr, "duplicated id \"%s\"\n", k);
+        exit(1);
+    }
+    map_append(m, k, v);
+}
+
+uintmax_t
+map_get(struct map *m, const char *k)
+{
+    uintmax_t *p = map_find_slot(m, k);
+    if (p == NULL) {
+        fprintf(stderr, "id \"%s\" not found\n", k);
+        exit(1);
+    }
+    return *p;
+}