This command converts an appdash trace into a pprof file for use with
`go tool pprof`. Spans are converted into stacks by sampling each root
span at a given rate and recording the stack of subspans at each sample.
These changes also replace the conditional addition of experimental and
debug commands with conditional visibility. Experimental and debug
commands will always be available, but will be hidden unless the
appropraite environment variables are set.
Co-authored-by: Levi Blackstone <levi@pulumi.com>