Feature: #69459 - Show tt_content preview in page module via Fluid

See forge#69459


A new PageTSconfig option allows to render a preview of a single content element in the Backend via Fluid.

The following option allows to override the default output of a content element via PageTSconfig:

mod.web_layout.tt_content.preview.media = EXT:site_mysite/Resources/Private/Templates/Preview/Media.html

All content elements with CType "media" will then be rendered by the Fluid Template which can be rendered like:

<f:format.crop maxCharacters="200">{bodytext}</f:format.crop>

All properties of the tt_content record are available in the template directly. Any data of the flexform field pi_flexform is available with the property pi_flexform_transformed as an array.