Introduce Option to Include Similar Nodegroups in Expander Options

[BenHinthorne]

What type of PR is this?

/kind feature

What this PR does / why we need it:

This PR updates the gRPC expanders Options request to include SimilarNodegroupIds. The purpose of adding this option is two fold:

• So that users can use the similar nodegroups as part of their best options filtering via the gRPC expander.
• When used alongside the flag introduced in this PR (todo: link to Rahul's PR), this would allow users to also filter which similar nodegroups would be included as part of the option. This allows for a more granular customization of the scaling options by the user, via their custom gRPC expander.

An example use case for why users may want to filter the similar nodegroups in the gRPC expander is to filter nodegroups by a maximum number of nodes per zone, to prevent scaling in zones that experience IP Exhaustion (link issue). Another example would be that this allows users to prevent upscaling in zones in which they may have an outage, via filtering out these options via their gRPC expander.

It's also worth noting that the the other built-in expanders have SimilarNodegroups included by default, because the expander.Option type includes similar nodegroups, it was only the *protos.Option type which did not.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.: