Add compression option for texture dumps.

Enable through command line options:
-C Graphics.Settings.TexturePNGCompressionLevel=[0-9]

Or from GFX.ini:
[Settings]
TexturePNGCompressionLevel=[0-9]

@see #10792

Source/Core/VideoCommon/TextureCacheBase.cpp

@@ -1023,7 +1023,7 @@ void TextureCacheBase::DumpTexture(RcTcacheEntry& entry, std::string basename, u
   if (File::Exists(filename))
     return;
 
-  entry->texture->Save(filename, level);
+  entry->texture->Save(filename, level, Config::Get(Config::GFX_TEXTURE_PNG_COMPRESSION_LEVEL));
 }
 
 // Helper for checking if a BPMemory TexMode0 register is set to Point