[MoE] Add Comprehensive MoE Integration Tests

[Jonahcb]

Motivation

This PR adds a comphrensive suite of MoE integration tests to add test coverage for MoE models from beginning to end. Currently, MoE code is only tested tangentially through the testing of other features (i.e., quantization).

Modifications

Added test file test/srt/layers/moe/test_moe_runners.py with integration tests.

Accuracy Tests

Benchmarking and Profiling

Checklist

• Format your code according to the Format code with pre-commit.
• Add unit tests according to the Run and add unit tests.
• Update documentation according to Write documentations.
• Provide accuracy and speed benchmark results according to Test the accuracy and Benchmark the speed.