[InstrProf] Use BalancedPartitioning to order temporal profiling trace data

In [0] we described an algorithm called //BalancedPartitioning// (bp) to consume function traces [1] and compute a function order that reduces the number of page faults during startup.

This patch adds the `order` command to the `llvm-profdata` tool which uses bp to output a function order that can be passed to the linker via `--symbol-ordering-file=`.

Special thanks to Sergey Pupyrev and Julian Mestre for designing this balanced partitioning algorithm.

[0] https://discourse.llvm.org/t/rfc-temporal-profiling-extension-for-irpgo/68068
[1] https://reviews.llvm.org/D147287

Reviewed By: spupyrev

Differential Revision: https://reviews.llvm.org/D147812