Views tokens need to be valid Twig variables; subtoken separator now double underscore instead of dash

When you override a field in views you can use twig with a set of placeholders coming from the different field columns. Unfortunately some of these tokens were using a dash and were therefore not valid Twig variable names and resulted in Twig expressions instead. This meant that the token output was incorrect. After this change, the subtokens will be separated by using double underscores.

Before this change, e.g., the language field offered these placeholders:

• langcode
• langcode-value

so you could override the language field output using e.g.

{{ langcode }} ({{ langcode-value}})

for showing the rendered language name (first) also the internal language code (second). However langcode-value is a Twig expression and is computed instead of being replaced as one value.

After this change, these are:

{{ langcode }} ({{ langcode__value}})