Use `wp_json_encode()` to safely render text inside `script` tag

[westonruter]

Given this existing code:

button.innerText = '<?php esc_html_e( 'Preview', 'preview-revisions' ); ?>';

It could be that a translation string incorporates an apostrophe, either because the language uses apostrophes:

Which would result in a syntax error here:

button.innerText = 'mua'i va'aiga';
// --------------------^

Or it could be that someone is maliciously adding apostrophes to attempt a translation string injection attack.

This is addressed by using wp_json_encode() when rendering text inside of script tag.

Issue - #2

[hbhalodia]

Thanks, @westonruter, for the patch. Seems good to me. I would create an issue for this, and then we can safely merge this.

[hbhalodia]

This is tested successfully, hence merging and closing the issue mentioned.