Flops profiler support einops.einsum

[lvhoaa]

• Added support for FlopsProfiler to include einops.einsum operation
• Added _patch_miscellaneous_operations() and _reload_miscellaneous_operations() to include this operation and potentially include other miscellaneous operations in the future
• Added _einops_einsum_flops_compute() that mimic already-existed _einsum_flops_compute()

[lvhoaa]

@microsoft-github-policy-service agree

[loadams]

Hi @lvhoaa - it looks like this PR (#6462) will be merged first that adds einops to the main requirements file, so you can remove the added to requirements-dev and that should fix the issues that we are seeing on this PR.