Refactor generate_profile.py

This refactors how benchmark arguments are stored and how the command
line is generated. Add in a Benchmark class to hold the data. Split out
benchmark arguments from Chrome enabled and disabled feature lists.

This CL changes how the per story benchmark command lines are generated.
Instead of dropping all arguments beyond first two it removes any
benchmark arg starting with --story, which matches --story-tag-filter or
--story, and keep all the other arguments.

Bug: 384737794
Change-Id: I93ef98f7805bec0dab3b7e7c5a51d8a20505725b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6603134
Commit-Queue: Kyle Charbonneau <kylechar@chromium.org>
Reviewed-by: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1468147}