Allow grouping context menus with only 2 children

[sikhote]

Is your feature request related to a problem? Please describe.

We are looking to create nested items with only 2 options within. Currently, 4 options are required, otherwise the options will not be grouped.

Describe the solution you'd like

I would like to change the requirements from 4 to 2, if possible.

Describe alternatives you've considered

N/A

Additional context

This is supporting some additions to the alerting plugin, which will be integrating into the main dashboard's context menus. We are adding a context menu for some visualizations. See screenshot below of what we wish to accomplish, but with only 2 options inside the Alerting menu.

[seanneumann]

Is this related to #2880 ??

[sikhote]

@seanneumann I think it's related, but I will refer to @lezzago to answer.

[joshuarrrr]

Interesting. I can see solid reasons for the previous requirement, but also how it would be useful to leverage grouping more explicitly. Reducing the minimum to 2 seems reasonable, but we'll need to make sure existing dev guidance (both docs and example plugins) are updated as part of the change.

[joshuarrrr]

@sikhote After chatting with other maintainers, this seems like a fine change, and makes sense in the context of the anywhere feature. Feel free to proceed with the draft PR.