Update test descriptions to active tense

[devin-ai-integration[bot]]

Update test descriptions to active tense in SignatureController.test.ts

This pull request updates the test descriptions in the SignatureController.test.ts file located in the packages/signature-controller folder. The test descriptions have been updated from passive to active tense to improve clarity and conciseness.

Changes Made

• Updated test descriptions in SignatureController.test.ts to active tense.
• Ensured that all test descriptions containing the word 'should' have been updated.

Example of Changes

• From: it('should return false when an error occurs', () => {})
• To: it('returns false when an error occurs', () => {})

Link to Devin run

This Devin run was requested by Bryce.