Moved the memory allocator and its util functions out of the EIP712 subdirectory and gave it its own compilation flag

Also removed dead code

src_common/mem_utils.c

@@ -0,0 +1,66 @@
+#ifdef HAVE_DYN_MEM_ALLOC
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "mem.h"
+#include "mem_utils.h"
+
+/**
+ * Format an unsigned number up to 32-bit into memory into an ASCII string.
+ *
+ * @param[in] value Value to write in memory
+ * @param[out] length number of characters written to memory
+ *
+ * @return pointer to memory area or \ref NULL if the allocation failed
+ */
+char    *mem_alloc_and_format_uint(uint32_t value, uint8_t *const length)
+{
+    char        *mem_ptr;
+    uint32_t    value_copy;
+    uint8_t     size;
+
+    size = 1; // minimum size, even if 0
+    value_copy = value;
+    while (value_copy >= 10)
+    {
+        value_copy /= 10;
+        size += 1;
+    }
+    // +1 for the null character
+    if ((mem_ptr = mem_alloc(sizeof(char) * (size + 1))))
+    {
+        snprintf(mem_ptr, (size + 1), "%u", value);
+        mem_dealloc(sizeof(char)); // to skip the null character
+        if (length != NULL)
+        {
+            *length = size;
+        }
+    }
+    return mem_ptr;
+}
+
+/**
+ * Allocate and align, required when dealing with pointers of multi-bytes data
+ * like structures that will be dereferenced at runtime.
+ *
+ * @param[in] size the size of the data we want to allocate in memory
+ * @param[in] alignment the byte alignment needed
+ *
+ * @return pointer to the memory area, \ref NULL if the allocation failed
+ */
+void    *mem_alloc_and_align(size_t size, size_t alignment)
+{
+    uint8_t align_diff = (uintptr_t)mem_alloc(0) % alignment;
+
+    if (align_diff > 0) // alignment needed
+    {
+        if (mem_alloc(alignment - align_diff) == NULL)
+        {
+            return NULL;
+        }
+    }
+    return mem_alloc(size);
+}
+
+#endif // HAVE_DYN_MEM_ALLOC