[#161980170] Removes 505 error for invalid user/parcel id

[ipaullly]

What does this PR do?

catches the instances where a user may submit a wrong id when canceling or retrieving orders by a specific user_id

Description of Task to be completed?

• Define a method in parcels model to check whether id passed into it exists in the database
• add logic to view functions to raise an error message when invalid id is passed through the URL

How should this be manually tested?

access the API documentation at https://documenter.getpostman.com/view/4014888/RzZCCwun, press the Run in Postman at the top right corner of the window. Try to send the endpoints that require a user/parcel id with an invalid id and an error message appears promptly

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (develop@0832a2a). Click here to learn what that means.
The diff coverage is 84.44%.

@@           Coverage Diff           @@
##             develop   #43   +/-   ##
=======================================
  Coverage           ?   85%           
=======================================
  Files              ?    11           
  Lines              ?   280           
  Branches           ?    17           
=======================================
  Hits               ?   238           
  Misses             ?    37           
  Partials           ?     5

Impacted Files	Coverage Δ
app/api/v1/__init__.py	100% <100%> (ø)
app/tests/v1/test_login.py	100% <100%> (ø)
app/auth/v1/__init__.py	100% <100%> (ø)
app/api/v1/models.py	100% <100%> (ø)
app/tests/v1/test_register.py	100% <100%> (ø)
app/tests/v1/test_parcels.py	100% <100%> (ø)
app/utilities/validation_functions.py	36.36% <36.36%> (ø)
app/auth/v1/views.py	58.97% <58.97%> (ø)
app/tests/v1/test_edgecases.py	64% <64%> (ø)
app/auth/v1/models.py	84.61% <84.61%> (ø)
... and 1 more

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