Implement python bindings for profiler

[yehudaorel]

Overview

Related to: https://github.com/OpenNMT/CTranslate2/issues/1736 ,will also resolve: https://github.com/OpenNMT/CTranslate2/issues/1734

Expose profiler functionality - ctranslate2::init_profiling() & ctranslate2::dump_profiling() to python level.

Example usage:

import ctranslate2

# Initialize the profiler on CPU
ctranslate2.init_profiler(device = ctranslate2.Device.cpu, 1)

Load model, generate/translate...

# Dump profiling to stdout
ctranslate2.dump_profiler()