Language export form options do not match what they export

Problem/Motivation

The language export form on 3.0.x replaced the Drupal 7 checkboxes with two sets of radios: "Download untranslated and translated strings / Download only translated strings" and "No metadata / Include metadata". The first option is wired to the exporter's template flag, so picking "untranslated and translated strings" produces a .pot template without a single translation, the opposite of what the label promises. The metadata choice never reaches the export query: the query picks its translation join from the template flag instead of the compact flag, so it only worked by accident for the default choice.

In Drupal 7 the form has three checkboxes: "Add @language translations" (off gives a template), "Add @language suggestions" and "Verbose output" (off gives a compact file without comments and without untranslated strings).

Steps to reproduce

Proposed resolution

Restore the Drupal 7 options with their labels and descriptions, and pass the compact flag through to the export query, where it decides the join as in Drupal 7. Templates skip the translation joins entirely.

One Drupal 7 behaviour is kept as is: without "Add suggestions" the query filters on the translation's suggestion column, which drops untranslated strings from verbose files too. Untranslated strings only appear when suggestions are added. Both tests now assert exactly that so a later change is a conscious one.

Tests: the Drupal 7 testExport() gained the verbose, suggestions and compact cases first, and the port L10nExportTest checks the same, plus the D7 default state of the checkboxes.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet

LLM disclosure

LLM was used to find, diagnose explain and fix this issue. With human review.