Improve Tachyon UX

pablogsal

This is a meta issue to group all the items to improve the UX of the tachyon profiler.

Tasks

Standardize timing arguments — Currently mixing µs and seconds for related timing args, which is confusing
Duration should default to "until done" - The fact that we sample only for 10 seconds by default is confusing to users and a bad experience

Auto-open browser with results — Reduce manual steps in the workflow; add --no-browser flag to disable

Hide runner/bootstrap frames by default — Top rows showing interpreter startup aren't useful for most profiling tasks
The Gil/gc/exception indicators could be progress bars — this probably will show the information more clearly and take less space
Show module names instead of full file paths — /home/user/project/pkg/mod.py → pkg.mod for readability
Show "self" time for functions — Display time spent in function body excluding callees, not just total inclusive time
Move hotspots to top of sidebar — This is the most important info; currently buried below logo and stats
Fix inverted flamegraph width — Currently shows narrow chart when leaves sum to small percentage, wasting screen space

Fix docs: -o output format — Docs imply text output but it's actually binary pstats format
Standardize --pstats behavior — Output format differs significantly with/without -o flag, which is unexpected

Thanks @dmoisset 🖤