Allow altering the results, especially visible link text (alter hook)

Problem/Motivation

Sometimes outputting the node title for a mention is not perfect, e.g. if it misses or contains other properties.

Being able to alter the results and especially the resulting link text through a hook would make things a lot more flexible.

Steps to reproduce

Proposed resolution

Let's add two alter hooks in src/MentionsType/MentionsTypeBase.php

• hook_ckeditor_mentions_build_token_alter()
• per entity, providing the entity as second parameter allowing to alter $result[$id] as first parameter. This will allow easy access to other entity properties
• hook_ckeditor_mentions_build_tokens_alter() to simply allow altering the results array.

Remaining tasks

User interface changes

API changes

Data model changes