Allow querying by root owner

[shifuma]

TLDR: There are times when it would be nice to get deeply nested entries, without needing to go through all levels: craft.entries().field('nestedMatrixField').rootOwner(entry).all()

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Some more information on my setup:

• Events have various relation and other fields (category, date, day of the week etc)
• Companies - a Matrix field on Events
• Presentations - a Matrix field on Companies

On a company's page, I am listing all of their presentations. However, I want to then filter those based on fields on Events. For example, from Company A's page, I want to see all of their presentations made at Events on a Saturday. That's where I thought this would be perfect.

-- `companies/_entry.twg` --
{% set events = craft.entries().section('events').dayOfTheWeek('Saturday').ids()
{% set presentations = craft.entries().field('presentations').rootOwnerId(events).all() %}

[shifuma]

Related: #15534