Add missing test to CryptoSquareTest (54-character input)

[Snehitha9126]

This PR adds a missing canonical test case for the 'crypto-square' exercise based on the uuid 33fd914e-fa44-445b-8f38-ff8fbc9fe6e6 from problem-specifications. It verifies that a 54-character plaintext results in 8 chunks with trailing spaces.

Reference: https://github.com/exercism/java/issues/2959

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Notes for merge:

• The change in problem specification looks like a test description change.

[no important files changed]