feat: implement deletion of prepared query

[vchandela]

• fixes #4

• Discussion thread: https://github.com/spirit-labs/tektite/discussions/226

• Local testing

  • Created a prepared query my_query
  • Tried deleting prepared query my-query (hypen instead of underscore). As expected this threw an error.
  • However, prepared query my_query was successfully deleted.

• Screenshots of all 3 terminals used for local testing:

  • terminal-1

  • terminal-2

  • terminal-3
    

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