fix(MediaFiles): return missing 'lastModified' and 'end' attributes

[ath0mas]

Platforms affected

www

Motivation and Context

Returned MediaFiles objects for captured media are missing lastModified (null) and end (0).

Description

The helpers.wrapMediaFiles method is using the MediaFile empty constructor, and attributes are set afterward.
But given MediaFile constructor is simply calling its parent cordova-plugin-file.File constructor, we can understand that some File attributes will never be redefined properly.

Directly calling the constructor with all the params values resolves this problem in a clean manner.

Testing

Returned MediaFiles objects now have correct lastModified === lastModifiedDate, and end === size.

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

[erisu]

Code changes LGTM