simpleperf: Support large branch list file

The branch list file is currently limited by the maximum size of
a protobuf message, which is 2GB. This change removes that
limitation by splitting the data into multiple messages.

Bug: 377769682
Test: run simpleperf_unit_test
Change-Id: I293a98ed260ebb1917defb07def0cfcb21a66328
6 files changed