ci/cd: trigger URL checks more, and limit amount

Key changes:

- Run URL checks more frequently on every change.
- Introduce environment variable to randomly select and limit URLs
  tested, this way the tests will provide quicker feedback on code
  changes.

Other supporting changes:

- Log more information about test before running the test to enable
  easier troubleshooting.
- Move shuffle function for arrays for reusability and missing tests.

tests/unit/application/Common/Shuffle.spec.ts

@@ -0,0 +1,52 @@
+import { describe, it, expect } from 'vitest';
+import { shuffle } from '@/application/Common/Shuffle';
+
+describe('Shuffle', () => {
+  describe('shuffle', () => {
+    it('returns a new array', () => {
+      // arrange
+      const inputArray = ['a', 'b', 'c', 'd'];
+      // act
+      const result = shuffle(inputArray);
+      // assert
+      expect(result).not.to.equal(inputArray);
+    });
+
+    it('returns an array of the same length', () => {
+      // arrange
+      const inputArray = ['a', 'b', 'c', 'd'];
+      // act
+      const result = shuffle(inputArray);
+      // assert
+      expect(result.length).toBe(inputArray.length);
+    });
+
+    it('contains the same elements', () => {
+      // arrange
+      const inputArray = ['a', 'b', 'c', 'd'];
+      // act
+      const result = shuffle(inputArray);
+      // assert
+      expect(result).to.have.members(inputArray);
+    });
+
+    it('does not modify the input array', () => {
+      // arrange
+      const inputArray = ['a', 'b', 'c', 'd'];
+      const inputArrayCopy = [...inputArray];
+      // act
+      shuffle(inputArray);
+      // assert
+      expect(inputArray).to.deep.equal(inputArrayCopy);
+    });
+
+    it('handles an empty array correctly', () => {
+      // arrange
+      const inputArray: string[] = [];
+      // act
+      const result = shuffle(inputArray);
+      // assert
+      expect(result).have.lengthOf(0);
+    });
+  });
+});