release(15.1.0): updated release notes & version

[erisu]

Motivation and Context

Prepare 15.1.0 release

Description

• Update Version (package, package-lock, and CordovaWebView)
• Added 15.1.0 Release Notes

Testing

• npm test

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.20%. Comparing base (61ebdcd) to head (034075d).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1976   +/-   ##
=======================================
  Coverage   63.20%   63.20%           
=======================================
  Files          24       24           
  Lines        4922     4922           
=======================================
  Hits         3111     3111           
  Misses       1811     1811           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.