Use subqueryload for all joins in get_screenshots

[KIRA009]

What kind of change does this PR introduce?
This PR fixes a bug with loading strategies

Summary
FIxes a bug where different loading strategies are used to access the same relation, resulting in a mapping error. This is fixed by using the same subqueryload across all loads, as it is recommended for loading data when the related data is in large numbers

Checklist

• My code follows the style guidelines of OpenAdapt
• I have performed a self-review of my code
• If applicable, I have added tests to prove my fix is functional/effective
• I have linted my code locally prior to submission
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (e.g. README.md, requirements.txt)
• New and existing unit tests pass locally with my changes

How can your code be run and tested?

Run the project, go to any recording detail page, and ensure that the page is rendered with the correct screenshots and action event data

Other information

[abrichr]

LGTM