utils: print out DLL metadata (#596)

## Link to GitHub Issue or related Pull Request, if one exists
#592 

## Description of change
* when custom DLLs are detected (`d3d9.dll`) print out some basic data
from the PE header
* for our own NVIDIA DLL stubs, add manifest files to identify ourselves
* as a bonus, when DLL hooks are loaded from `-k`, print DLL info there
as well

This is mainly to detect when DXVK is in use.

src/spice2x/util/libutils.h

@@ -77,4 +77,6 @@ namespace libutils {
     intptr_t rva2offset(const std::filesystem::path &path, intptr_t rva);
     intptr_t offset2rva(IMAGE_NT_HEADERS *nt_headers, intptr_t offset);
     intptr_t offset2rva(const std::filesystem::path &path, intptr_t offset);
+
+    void print_dll_info(std::filesystem::path filename);
 }