Update system connection delete route

[TheAndrewJackson]

Closes #3739

Description Of Changes

Update the FE to use the delete connection delete route. It also fixes a couple issues with the delete route

Code Changes

• Update frontend to use new delete route
• Fix some small issues with the delete route in the BE
• Update BE tests

Steps to Confirm

• Run fides and the admin ui
• create a system and an integration
• delete the integration

Pre-Merge Checklist

• All CI Pipelines Succeeded
• Documentation:
  • documentation complete, PR opened in fidesdocs
  • documentation issue created in fidesdocs
• Issue Requirements are Met
• Relevant Follow-Up Issues Created
• Update CHANGELOG.md
• For API changes, the Postman collection has been updated

[cypress]

Passing run #3203 ↗︎

0	4	0	0	0
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Details:

Merge 7a34b0e into aa76b4b...
Project: fides	Commit: 954eb936d5 ℹ️
Status: Passed	Duration: 01:03 💡
Started: Jul 19, 2023 12:01 PM	Ended: Jul 19, 2023 12:03 PM

_{This comment has been generated by cypress-bot as a result of this project's GitHub integration settings.}