refactor: remove dependency cross-fetch

[CHC383]

close #126

cross-fetch is not needed in the modern environments, as fetch is available in the browsers and Node >= 18.

To minimize the changes on the tests,

• nock is updated to v14 which supports native fetch
• jest-fixed-jsdom is used as the browser test environment due to https://mswjs.io/docs/migrations/1.x-to-2.x#requestresponsetextencoder-is-not-defined-jest

[curusarn]

Thank you for the contribution @CHC383!

I'll get someone from the team to review this.

Thanks again for the PR!