Profiling example

[jalas167]

Example that profile providers, partially taken from yapapi examples:

• Take parts of blender example
• Run render of the same frame on multiple providers
• Check times that took provider to render single frame
• Outputs list of profiled providers, preferably sorted
• Flow of the example:
  • Create a demand
  • Listen to proposals until example exit
  • Run frame render on each arrived proposal
  • Display stats of provider render
  • Display summary of providers at example exit