Bug 1736346 - Expose the @mozilla/glean/web entry point

[brizental]

In this PR I only enpose the entry point. Actual implementation of the web platform will come in the next PRs.

Also, is it confusing to call the website entry point web?

Pull Request checklist

• Quality: Make sure this PR builds and runs cleanly.
  • Inside the glean/ folder, run:
    • npm run test Runs all tests
    • npm run lint Runs all linters
• Tests: This PR includes thorough tests or an explanation of why it does not
  • https://bugzilla.mozilla.org/show_bug.cgi?id=1736351
• Changelog: This PR includes a changelog entry to CHANGELOG.md or an explanation of why it does not need one
• Documentation: This PR includes documentation changes, an explanation of why it does not need that or a follow-up bug has been filed to do that work
  • https://bugzilla.mozilla.org/show_bug.cgi?id=1736352

[mdboom]

LGTM. Regarding your question about the entrypoint "web", maybe "browser" is clearer? But I'm not strongly opposed to "web" either.

[brizental]

Regarding your question about the entrypoint "web", maybe "browser" is clearer

I worry that browser would be confusing because webext folks may think that is their entry point as well. However, web has the same issue hah.