Internal: Prepare new browser manager interface and recreated finder

[yhatt]

Related: #565

Note

This change should not introduce any major change of the behavior into current Marp CLI.

This PR prepares new browser manager interface classes and the recreated browser finders including Firefox support.

await findBrowser()
/*
{
  path: '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome',
  acceptedBrowsers: [
    [class ChromeBrowser extends Browser] {
      kind: 'chrome',
      protocol: 'webdriver-bidi'
    },
    [class ChromeCdpBrowser extends Browser] {
      kind: 'chrome',
      protocol: 'cdp'
    }
  ]
}
*/

findBrowser() returns Promise to resolve automatically detected browser path and its supported browser classes. In next major release v4, we are planning it would be used for converting Markdown (WebDriver BiDi) and launching preview window (CDP).