chore: refactored saved query id parameter to always expect int64

[superlinkx]

Description

Updated usage of the saved_query.id field to always expect int64. This includes reading the value in from the API handler and passing through to the database functions.

Motivation and Context

This PR addresses: BED-4698

Light refactoring to make savedQueryID usages more consistent overall, including always treating as an int64 and using the same naming conventions everywhere.

How Has This Been Tested?

Existing tests pass, no functional changes

Screenshots (optional):

Types of changes

• Chore (a change that does not modify the application functionality)

Checklist:

• I have met the contributing prerequisites
  • Assigned myself to this PR
  • Added the appropriate labels
  • Associated an issue: Issues and Pull Requests README #672
  • Read the Contributing guide: https://github.com/SpecterOps/BloodHound/wiki/Contributing
• I have ensured that related documentation is up-to-date
  • Open API docs
  • Code comments (GoDocs / JSDocs)
• I have followed proper test practices
  • Added/updated tests to cover my changes
  • All new and existing tests passed

[stephanieslamb]

Thank you for making this more consistent!