[TASK] Add additional fields to version table for TER v1 migration

Four new fields are added to the tx_terfe2_domain_model_version table, which are migrated through a one-time-command "ter:migratedetailstov2" from TER v1 tables, and updated on TER v1 Upload as well.

These fields are available in a normalized way, but are also needed flat for the extensions.xml.gz file, which makes the SQL query for building the XML faster in the future (next update), and allows for dropping the tx_ter_extensions table in the next iteration.

The fields are currently not added to TCA as they serve no purpose (yet) for the frontend as it is up to decide if we keep the "*_authors" table or keep the extension version information in the main *_version table.