Fix unhandled exceptions in API views causing 500 errors (Issue #10)

[thunderbird7413]

Summary

This PR fixes multiple cases where API views were throwing 500 Internal Server Errors due to unhandled native Python exceptions.
These failures were previously worked around in Issue #8 using assertRaises. This change addresses the root cause by adding proper exception handling in the views and updating the test suite accordingly.

What was fixed

API View Error Handling

• Added basic exception handling to prevent crashes on invalid input
• Views now return 400 Bad Request instead of 500 errors for:

Malformed tags
Non-numeric coordinates
Invalid / malformed JSON

Files updated

mainapp/api.py

Wrapped logic in lookup_tag, search_range, and search_full
Catches ValueError and json.JSONDecodeError
Returns HttpResponseBadRequest (400)

Routing Improvements

• Relaxed URL regex for search_range so invalid parameters reach the view instead of returning 404.
• Reordered URL patterns to avoid conflicts (search_title before search_range).

Files updated

mainapp/urls.py

Test Suite Updates

• Updated API tests to assert 400 responses instead of raised exceptions.
• Removed reliance on assertRaises (Issue Add Preliminary Test Coverage #8 workaround).
• Mocked external GLB validation to prevent OS-specific failures.
• Fixed filesystem and path assertions to work reliably on Windows.

Files updated

• test_lookup.py
• test_model.py
• test_forms.py
• test_nightly.py
• mixins.py

Verification

• python manage.py test mainapp.tests.api.test_lookup
• Full test suite: 118 tests passing
• No unhandled exceptions

[AyushDharDubey]

Apart from these, as a general practice, try to segregate different changes in meaningful independent commits (for eg, .gitignore change, settings.py change, test addition/updates, should have been separate commits)

Also, It would be nice to see fix for:

3dmr/mainapp/tests/views/test_model.py

Lines 395 to 397 in cfb15c7

	# def test_revise_non_existent_model_id(self):
	# response = self.client.get(reverse('revise', args=[99999999]))
	# self.assertEqual(response.status_code, 404)

[AyushDharDubey]

Apart from these, there are commented out pieces of code from the previous iteration which needs to be removed

[AyushDharDubey]

Just a few tiny nit picking and then we are ready to merge.
Also, this PR has been bloated with commits along with the review iterations, would you be able to squash the commits into 2 or 3 with meaningful commit messages and force push.

[AyushDharDubey]

Also, some of the tests could be extended to test the output more thoroughly. In particular, it is always good to have tests to ensure that something does not happen

Originally proposed by @lonvia in #8 (review)

In case you would you like to enhance the test suite further, this one would need to go in a separate PR.