Added some checks for resolvers after removes

[barankyle]

Summary

Avatar removal was returning errors. This was caused by the avatarResolver fetching model and thumbnail static-resources, but on avatar deletion, these have been removed, which makes the .get's error. Made this not trigger when context.event is 'removed', and applied this to other resolvers that fetch static-resources.

Cleaned up some redundant function calls that are assigned to variables before just returning the variable.

🤖 Generated by Copilot at 94fcdac

This pull request refactors and optimizes various virtual fields in the resolvers of different entities in packages/server-core/src. It removes unnecessary conditions, variables, and return statements, and avoids database queries for deleted entities. The purpose is to improve the performance, readability, and error handling of the resolvers.

References

closes #8930

Explanation

🤖 Generated by Copilot at 94fcdac

• Avoid unnecessary database queries and errors when bots, instances, avatars, or users are deleted by checking the context.event (link, link, F12L36L36, link)
• Simplify virtual fields for various entities by removing if conditions, intermediate variables, and redundant return statements and returning the query results directly (link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link, link)

🤖 Generated by Copilot at 94fcdac

We are the masters of the code
We slash the queries and the load
We make the fields concise and clear
We crush the errors and the fear

QA Steps

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Checklist

• If this PR is still a WIP, convert to a draft
• When this PR is ready, mark it as "Ready for review"
• ensure all checks pass
• Changes have been manually QA'd
• Changes reviewed by at least 2 approved reviewers