feat: implement Innertube#resolveURL(url)

[LuanRT]

Description

Adds support for resolving URLs with InnerTube's /navigation/resolve_url endpoint.

Usage

import { Innertube, UniversalCache } from 'youtubei.js';

(async () => {
  const yt = await Innertube.create({ cache: new UniversalCache() });
  const response = await yt.resolveURL('https://www.youtube.com/@pewdiepie');
  console.log(response);
})();

Output:

NavigationEndpoint {
  type: 'NavigationEndpoint',
  payload: { browseId: 'UC-lHJZR3Gqxm24_Vd_AJ5Yw', params: 'EgC4AQDyBgQKAjIA' },
  metadata: {
    url: '/youtubei/v1/navigation/resolve_url',
    page_type: 'WEB_PAGE_TYPE_CHANNEL',
    api_url: 'browse'
  }
}

Closes #116

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have checked my code and corrected any misspellings