Add more and unify tests for absent object cases

- Unify test data for nonexistence of an object/string and collection.
- Introduce more test through adding missing test data to existing tests.
- Improve logic for checking absence of values to match tests.
- Add missing tests for absent value validation.
- Update documentation to include shared test functionality.

tests/unit/shared/Assertions/ExpectThrowsAsync.ts

@@ -0,0 +1,17 @@
+import { expect } from 'chai';
+
+export async function expectThrowsAsync(
+  method: () => Promise<unknown>,
+  errorMessage: string,
+) {
+  let error: Error;
+  try {
+    await method();
+  } catch (err) {
+    error = err;
+  }
+  expect(error).to.be.an(Error.name);
+  if (errorMessage) {
+    expect(error.message).to.equal(errorMessage);
+  }
+}