CB-13690 : (browser) Add src change to method to Media object

[f0wu5u]

New method to change node src when change audio src, best for playing multiple files/url

Release method now unset node src to empty to cancel ongoing network request before collecting garbage

Platforms affected

browser

What does this PR do?

Add audio src change to media object

What testing has been done on this change?

Checklist

• Reported an issue in the JIRA database
• Commit message follows the format: "CB-3232: (android) Fix bug with resolving file paths", where CB-xxxx is the JIRA ID & "android" is the platform affected.
• Added automated test coverage as appropriate for this change.

[janpio]

jshint is failing:

> cordova-plugin-media@5.0.1-dev jshint /home/travis/build/apache/cordova-plugin-media
> jshint www && jshint src && jshint tests
www/browser/Media.js: line 203, col 2, Missing semicolon.
1 error

[janpio]

Tests are now passing.

[f0wu5u]

Review: Change media src for platform:browser now stops previous stream src