Add test for Bio::SeqI interface using mock class

[HussainAther]

This PR adds a new unit test file t/SeqI.t that provides basic test coverage for the Bio::SeqI interface. A mock implementation class is defined inline to test method expectations like display_id, seq, etc.

[Copilot]

Pull Request Overview

This PR introduces a new unit test for the Bio::SeqI interface by defining an inline mock implementation and verifying core methods.

• Adds t/SeqI.t with a MySeq mock class inheriting from Bio::SeqI
• Verifies display_id and seq return expected values

Comments suppressed due to low confidence (1)

t/SeqI.t:5

• The tests currently cover only display_id and seq. Consider adding assertions for desc and alphabet to fully exercise the Bio::SeqI interface methods.

use Test::More tests => 4;