Updates to datastore install to create a valid schema for post import…

[kaise-lafrai]

… result table

Fixes #4407

Describe your changes

Checkout this branch : 2.x

• run ddev dkan-site-install
• run ddev drush sqlc then describe dkan_post_import_job_status; and confirm id and timestamp fields DO NOT exist.
• running ddev drush updatedb DOES NOT do anything
• checkout this branch datastore-install-updates
• run ddev drush updatedb, confirm that datastore_update_9004 runs successfully.
• run ddev drush sqlc then describe dkan_post_import_job_status; and confirm id and timestamp fields exist.
• run through creating datasets and applying data dictionaries.
• confirm dashboard reflects the correct post import status at /admin/dkan/datastore/status

Checkout this branch: datastore-install-updates

• run ddev dkan-site-install
• run ddev drush sqlc then describe dkan_post_import_job_status; and confirm id and timestamp fields exist.
• run through creating datasets and applying data dictionaries.
• confirm dashboard reflects the correct post import status at /admin/dkan/datastore/status

Checklist before requesting review

If any of these are left unchecked, please provide an explanation

• I have updated or added tests to cover my code
• I have updated or added documentation

[janette]

LGTM

[dafeder]

Just noting that this is mysql-only code in the update hook. That's fine for now, update is not used for kernel tests so anything created temporarily in SQLite will be ok; a bunch of other places in the datastore also break on non-MySQL backends. Some day would be good to abstract this so its PostgreSQL and SQLite-compatible but not today :)