[allocations] fix growth of preallocated buffers

* Replace * 2 with * sizeof(WCHAR) for string usages
* Grow streams and other buffers reasonably, e.g. add 128 elements per
  try and check for possible overflows
* Add constant postfix to force them to 64bit

libfreerdp/crypto/base64.c

@@ -313,7 +313,7 @@ static inline char* base64_encode_ex(const BYTE* WINPR_RESTRICT alphabet,
 	if (crLf)
 	{
 		size_t nCrLf = (outLen + lineSize - 1) / lineSize;
-		extra = nCrLf * 2;
+		extra = nCrLf * 2ull;
 	}
 	size_t outCounter = 0;