Added ability generate unsecure URL if current URL is secure

[okorshenko]

Description

When calling getUrl from a secure connection ( HTTPS ) with param _secure = false we are getting secure URL instead of unsecured.

Fixed Issues (if relevant)

1. Unable to generate unsecure URL if current URL is secure #6175: Unable to generate unsecure URL if current URL is secure

Manual testing scenarios

Preconditions

Magento 2 version 2.3.0-dev
Use \Magento\Framework\Url::getUrl() from secure area of the store

###Steps to reproduce

Make sure code is executed in secure area of the store (HTTPS)
Generate URL in code
/**
* @var \Magento\Framework\Url
*/
protected $url;
...
$this->url->getUrl(
'test/test/test',
[
'_secure' => false
]
)

Expected result
http://example.com/test/test/test

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)