mtmd : add video input support (#24269)

* wip

* ok: lazy bitmap API

* remember to free lazy text

* wip

* add mtmd_helper_video

* support video input on server (base64 input)

* add MTMD_VIDEO config

* add timestamp

* update CLI

* cli: allow auto-completion for video

* add --video arg

* fix build

* update docs

* rename as suggested

tests/test-mtmd-c-api.c

@@ -2,6 +2,7 @@
 #include <assert.h>
 
 #include "mtmd.h"
+#include "mtmd-helper.h"
 
 int main(void) {
     printf("\n\nTesting libmtmd C API...\n");
@@ -17,6 +18,11 @@ int main(void) {
         return 1;
     }
 
+    // simple test for the helper
+    size_t n_tokens_total = mtmd_helper_get_n_tokens(chunks);
+    printf("Total tokens in chunks: %zu\n", n_tokens_total);
+    assert(n_tokens_total > 0);
+
     size_t n_chunks = mtmd_input_chunks_size(chunks);
     printf("Number of chunks: %zu\n", n_chunks);
     assert(n_chunks > 0);