Breaking: #91906 - Store TransOrigDiffSourceField as json string

See forge#91906

Description

The TCA field ['tableName']['ctrl']['transOrigDiffSourceField'] - often set to l18n_diffsource - stores the state of the source language record a translated record has been created from. This is used if content in the source language of a record has been changed to hint editors for a potentially needed update of the translated record.

The storage format of this field has been changed from a PHP serialized string to a json encoded string.

Impact

Usages of this field can be expected to be core internal. The impact on existing instances in low since it's unlikely that an extension uses the field content.

Affected Installations

Installations with multi language sites are affected and should run the upgrade wizard.

Migration

Run "Admin Tools" -> "Upgrade" -> "Upgrade Wizard" -> "Migrate transOrigDiffSourceField field to json encoded string." to adapt existing rows to the new storage format.