Feature: #88907 - Always enable filter in SelectMultipleSideBySide fields

See forge#88907

Description

The filter functionality of fields type = select with renderType = selectMultipleSideBySide is always enabled now.

Impact

Before:

'tsconfig_includes' => [
   'label' => 'LLL:EXT:frontend/Resources/Private/Language/locallang_tca.xlf:pages.tsconfig_includes',
   'config' => [
      'type' => 'select',
      'renderType' => 'selectMultipleSideBySide',
      'size' => 10,
      'items' => [],
      'enableMultiSelectFilterTextfield' => true,
      'softref' => 'ext_fileref'
   ]
],
Copied!

Now just omit the line 'enableMultiSelectFilterTextfield' => true, the behaviour will stay the same.

A migration wizard is available that removes the option from your TCA and leaves a message where code adaption has to take place.