feat(c-miner): port miner pipeline to modular C implementation

types.c

@@ -0,0 +1,23 @@
+#include "types.h"
+
+#include <stdlib.h>
+
+void block_template_free(BlockTemplate *tpl) {
+    size_t i;
+
+    if (tpl == NULL) {
+        return;
+    }
+
+    for (i = 0; i < tpl->tx_count; ++i) {
+        free(tpl->transactions[i].data);
+        tpl->transactions[i].data = NULL;
+    }
+
+    free(tpl->transactions);
+    tpl->transactions = NULL;
+    tpl->tx_count = 0;
+
+    free(tpl->default_witness_commitment);
+    tpl->default_witness_commitment = NULL;
+}