add negative test for the _is_inchikey method in CompoundIdentifier class

[adebisi4145]

…lass

Thank you for taking your time to contribute to Ersilia, just a few checks before we proceed

• Have you followed the guidelines in our Contribution Guide
• Have you written new tests for your core changes, as applicable?
• Have you successfully ran tests with your changes locally?

Description

The _is_inchikey method in CompoundIdentifier class checks whether a given string is a valid InChIKey. This method checks whether the string provided is exactly 27 characters long, splits the string into 3 parts using hyphen (-) as the seperator and then ensure that the first part has 14 characters, the second part has 10 characters, and the third part has 1 character.

This PR adds negative test for the _is_inchikey method

Changes to be made

• Add negative test case for _is_inchikey

• Test the following invalid InChIKeys:
  No hyphens: BSYNRYMUTXBXSQUHFFFAOYSA
  Incorrect length: BSYNRYMUTXBXSQ-UHFFFAOYSA-XY
  Numerical characters: 12345678901234-1234567890-X
  Underscore instead of hyphens: BSYNRYMUTXBXSQ_UHFFFAOYSA-N
  No last part: BSYNRYMUTXBXSQ-UHFFFAOYSA

Status

• I added the negative test case for _is_inchikey

• I ran all tests locally here

To do

If this is a work in progress, Replace this line with your next steps

Is this pull request related to any open issue? If yes, replace issueID below with the issue ID

Related to #1319

[DhanshreeA]

Hey @adebisi4145 could you address the conflicts in this PR?