Create utility to render from the delegate in a file

[cpichard]

Currently the render delegate renders in a live buffer owned and managed by the usd hosts, like Houdini, usdview, etc. There are some solution to render in a file, like husk or usdrecord, for comparing the render produced by the delegate to the one produced by kick, however none are convenient and scalable.

We would like a command line tool which allows to render on disk using the render delegate code path.

Describe alternatives you've considered

• husk, need an Houdini license
• usdrecord needs python and doesn't allow to pass render params.

[sebastienblor]

See #840