vulkaninfo: Replace devsim with Profile json output

vulkaninfo: Replace devsim with Profile json output

Make vulkaninfo capable of printing Vulkan Profiles with the json output. This
replaces the current DevSim output and folds the portability schema output into
the regular JSON output.

Changes include:
* Printing to file by default if json output is chosen
* Cleaning up codegen for extension structs
* Fixing up the help message
* Consolidating the portability schema output into just json