feat: support batch node groups (aka zipped/pairwise batch nodes)

[psychedelicious]

Summary

Adds support for batch node groups.

Previously, multiple batch nodes were combined by taking the cartesian product of their collections and executing the workflow once per permutation.

For example, say we have 2 string batch nodes which route into a string join node:

This results in 2 * 2 = 4 workflow executions. Every possible combination of strings are fed into the join.

These are the outputs of the join:

• "a cute cat"
• "a cute dog"
• "a ferocious cat"
• "a ferocious dog"

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With batch node groups, all batch nodes in a group are first zipped together before the product is taken. The zipped group then functions like a single batch node in the product operation.

Set the two string batch nodes to the same group:

This will result in 2 executions. The string batch values are zipped/paired, so that the first items in both collections are used in the first execution, and the second items in both collections are used in the second execution.

These are the outputs of the join with the two batches grouped:

• "a cute cat"
• "a ferocious dog"

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Notes:

• Any number of batch nodes can be in a batch group.
• All batch nodes in a batch group must have the same number of items in their collections.
• Batch nodes must connect to something. No floating lonely batches.
• Grouped and ungrouped batch nodes can be combined arbitrarily in a workflow. The only limitation is you can have a max of 5 groups. Technically, the backend supports any number of groups, but 5 should be enough for 99.99% of use-cases and makes for a much simpler implementation.
• The Invoke button tooltip will tell you how many total executions will be queued.

Related Issues / Discussions

offline discussion

QA Instructions

Try it out.

Merge Plan

This PR is dependent on #7545.

Checklist

• The PR has a short but descriptive title, suitable for a changelog

[skunkworxdark]

Can these batch nodes take a collection input to build the list up elsewhere?

e.g. The string batch input could be fed via the prompts from file node

If not, could a load from file option be added to the node?

[psychedelicious]

Can these batch nodes take a collection input to build the list up elsewhere?

e.g. The string batch input could be fed via the prompts from file node

If not, could a load from file option be added to the node?

Batch and generator nodes cannot interact with with non-batch nodes. But we can do things like load prompts from file by implementing it in javascript. For example, load from file -> browse FS for file -> load and parse directly in the UI.