Add getByText in the browser module

[ankur22]

What?

This adds a convenience method on page to be able to select on elements with the text in the element.

Why?

This is part of the story of adding getBy*, which makes working with selectors a little easier. We used to have to work with the page.locator API providing either a CSS selector or a XPath selector if we wanted to get the element by the text in the element:

<div>Hello World</div>

// Not available in CSS
const l = page.locator('//div[text()="Hello World"]'); // XPath

Now we can use:

const l = page.getByText('Hello World');

Working with getBy* in general is an industry standard in the frontend testing world.

Checklist

• I have performed a self-review of my code.
• I have commented on my code, particularly in hard-to-understand areas.
• I have added tests for my changes.
• I have run linter and tests locally (make check) and all pass.

Checklist: Documentation (only for k6 maintainers and if relevant)

Please do not merge this PR until the following items are filled out.

• I have added the correct milestone and labels to the PR.
• I have updated the release notes: link
• I have updated or added an issue to the k6-documentation: grafana/k6-docs#NUMBER if applicable
• I have updated or added an issue to the TypeScript definitions: grafana/k6-DefinitelyTyped#NUMBER if applicable

Related PR(s)/Issue(s)

#4792, #4248

[codebien]

LGTM, mostly I have the same questions I submitted on the other pull request.

The base branch was changed.