common: fix missing exports in llama-common (#22340)

* common: refactor common/debug to move abort_on_nan into base_callback_data

Passing bool abort_on_nan as template parameter for common_debug_cb_eval is unnecessary and creates an issue with LTO.
It should just be a member of the base_callback_data instead.

* cont : cleanup

* common : use pimpl in debug.h to reduce header dependencies

Move common_debug_cb_user_data's data members (std::regex,
std::vector<uint8_t>) into a private impl struct in debug.cpp.

This removes the includes of common.h and <regex> from debug.h,
reducing transitive dependencies for any translation unit that
includes the header.

Assisted-by: llama.cpp:local pi

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

tools/mtmd/mtmd-cli.cpp

@@ -90,7 +90,7 @@ struct mtmd_cli_context {
     int n_threads    = 1;
     llama_pos n_past = 0;
 
-    base_callback_data cb_data;
+    common_debug_cb_user_data cb_data;
 
     mtmd_cli_context(common_params & params) : llama_init(common_init_from_params(params)) {
         model = llama_init->model();
@@ -145,7 +145,7 @@ struct mtmd_cli_context {
         mparams.image_max_tokens = params.image_max_tokens;
         if (std::getenv("MTMD_DEBUG_GRAPH") != nullptr) {
             mparams.cb_eval_user_data = &cb_data;
-            mparams.cb_eval = common_debug_cb_eval<false>;
+            mparams.cb_eval = common_debug_cb_eval;
         }
         ctx_vision.reset(mtmd_init_from_file(clip_path, model, mparams));
         if (!ctx_vision.get()) {