Add support for inline snapshots tests

### What is the problem this feature will solve? [Jest inline shapshots](https://jestjs.io/docs/snapshot-testing#inline-snapshots) are like file-based snapshots but much more casual. I love using them for small snapshots and I think they'd be a great improvement to Node.js. From Jest's docs, they look like: ```ts it('renders correctly', () => { const tree = renderer .create(<Link page="https://example.com">Example Site</Link>) .toJSON(); expect(tree).toMatchInlineSnapshot(` <a className="normal" href="https://example.com" onMouseEnter={[Function]} onMouseLeave={[Function]} > Example Site </a> `); }); ``` ### What is the feature you are proposing to solve the problem? The Node.js version might look like: ```ts test("renders correctly", async ctx => { const tree = renderer .create(<Link page="https://example.com">Example Site</Link>) .toJSON(); ctx.assert.snapshotInline(` <a className="normal" href="https://example.com" onMouseEnter={[Function]} onMouseLeave={[Function]} > Example Site </a> `); }); ``` ### What alternatives have you considered? I use file snapshots or `assert.deepEqual()`.