`Hint` with invalid index returns internal server error

[dblythy]

New Issue Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.
• I can reproduce the issue with the latest version of Parse Server.

Issue Description

When using hint, if an index that does not exist is specified, Internal server error is thrown.

Steps to reproduce

new Parse.Query('Test').hint('a').find()

Actual Outcome

Throws internal server error

Expected Outcome

Should return invalid hint

Environment

Server

• Parse Server version: 5.3.0
• Operating system: macos
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): local

Database

• System (MongoDB or Postgres): mongo
• Database version: 5.0
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): atlas

Client

• SDK (iOS, Android, JavaScript, PHP, Unity, etc): js
• SDK version: 3.5.0

Logs

[parse-github-assistant]

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