Fix simple image slider markup for Everblock (remove row/col in slider mode)

[CySSoO]

Motivation

• The front render used Bootstrap .row/.col-* wrappers even when display_mode == "slider", preventing a proper horizontal slider; the change aims to provide a native slider structure while preserving existing grid/columns behavior.

Description

• Updated the prettyblock_img.tpl slider branch to use a horizontal slider structure by removing the outer .row/.col-* wrappers in slider mode and keeping them for non-slider layout.
• Added a transition class to the .ever-slider-track element and kept existing item HTML (picture/img/link/lazyload) untouched.
• Ensured navigation buttons (.ever-slider-prev, .ever-slider-next) and pagination container (.ever-slider-dots) remain present inside the slider markup.
• Restored the original Bootstrap row wrappers only in the non-slider branch and fixed the opening/closing wrapper placement to avoid broken DOM nesting.

Testing

• No automated tests were executed for this change in this environment.
• The change was limited to the TPL markup (views/templates/hook/prettyblocks/prettyblock_img.tpl) and does not modify PHP configuration or external JS/CSS files.

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Codex Task