C++ 17 Compatibility

**Description**

Wrapper generation throws errors when it encounters C++ 17 features. For example:

```
INFO: Parsing Code
In file included from /tmp/tmpabzfnu6m.h:1:
In file included from Chaste/projects/PyChaste/dynamic/wrappers//wrapper_header_collection.hpp:9:
Chaste/global/src/FileFinder.hpp:42:21: error: expected namespace name
namespace fs = std::filesystem;
```