Allow searching for extensions
Currently we cannot search through extensions. We have to search for the application, scroll down and then install the extension. However, this can be quite unintuitive for users that would not know where to find the extension to begin with. Recently, in Flathub, two MRs have been submitted to extend Vulkan's functionality.
However, users will not expect to install them by searching for "Freedesktop platform", going to the platform page and then installing it. They'd want to simply search for "mangohud" or "vkbasalt" and install them, including myself.