[WIP] Predicate to search by length of string

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original issue description:

I have a rails API using ransack to filter results. I want to be able to query by the length of the string eg. I want to find all records where attribute a's length is less than a desired value.

name_length_lteq: 4 => should return all records with the name of 4 or less characters.

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Additional instructions:

Decide if this will be a performance drag before proceeding

Fixes #1492

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