[telemetry] Script for finding all Telemetry dependencies.

Given a list of Python modules, it will find all:
- bootstrap_deps folders, recursively.
- Python dependencies.
- Page sets in those modules' folders.
- Serving dirs of those page sets.
And print a list of all files, or zip them up.

Example bot command: tools/telemetry_tools/find_dependencies -v tools/perf/run_benchmark tools/perf/run_measurement tools/perf/record_wpr content/test/gpu/run_gpu_test -z telemetry.zip


BUG=311380
TEST=Ran it.

Review URL: https://codereview.chromium.org/103433002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251298 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251298