Fix for incorrectly escapeHtml'd JSON in commit b8f78cc6

[insanityinside]

This commit fixes a bug where the resize JSON configuration was incorrectly being HTML encoded before being output, preventing CMS image uploads in the admin due to the Javascript failing on the encoded single quote -> ' in the code. Relates to new resize code introduced in MAGETWO-94988, commit b8f78cc.

[magento-engcom-team]

Hi @insanityinside. Thank you for your contribution
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[orlangur]

Hi @insanityinside,

Please add annotation similar to https://github.com/magento/magento2/blob/2.3-develop/app/code/Magento/Cms/view/adminhtml/templates/browser/content/uploader.phtml#L156 and add more details on steps to reproduce to reveal an issue.

[insanityinside]

Changes made as requested.

Loading the upload image page on the latest 2.2-develop from the CMS page editor results in a javascript error in the console, due to the JSON being incorrectly encoded and being unable to be parsed. Attempting to add an image will trigger the error as soon as the AJAX page tries to load.

[magento-engcom-team]

Hi @orlangur, thank you for the review.
ENGCOM-3582 has been created to process this Pull Request

[magento-engcom-team]

Hi @insanityinside. Thank you for your contribution.
We will aim to release these changes as part of 2.2.8.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.

[insanityinside]

Forward port unnecessary, code is already fixed in 2.3-develop.