How to transfer data to another table using declarative schema?

I need to update the installation part of one extension from old to declarative schema.

Old system looks like:

Setup version – 1.0

Adds table vendor_entity

entity_id
name
desciption
status

Setup version – 2.0

Adds new table vendor_entity_locale

entity_locale_id
entity_id
name
desciption
store_id

with SQL method for moving data from vendor_entity to vendor_entity_locale

The fields name and description removed from vendor_entity and table looks like:

entity_id
status

As you can see the database schema was transforming for hold the store-related values in new specific table.

My Question – how can I achieve the same using the declarative schema?
The problem related to this rule statement: “Magento prioritizes the declarative schema and executes the declarative install schemas before the data and schema patches.”

So if I leave the final state (bin/magento setup:upgrade --convert-old-scripts=1) in db_schema.xml:

<table name="vendor_entity" resource="default" engine="innodb">
    <column xsi:type="int" name="entity_id" padding="10" unsigned="true" nullable="false" identity="true"/>
    <column xsi:type="text" name="name" nullable="false" disabled="true"/>
    <column xsi:type="text" name="description" nullable="false" disabled="true"/>
    <column xsi:type="smallint" name="status" padding="5" unsigned="true" nullable="false" identity="false" default="0" />
    <constraint xsi:type="primary" referenceId="PRIMARY">
      <column name="entity_id"/>
    </constraint>
  </table>

the clients who updated the extension from 1.0 version will lose name and description because database structure will be modified firstly (columns name and description will be deleted by schema) and than data won’t be found (for transferring to new table) in any data path script which will be executed after.

Here is the dry-run-installation.log:

ALTER TABLE `vendor_entity` DROP COLUMN `name`, DROP COLUMN `description`

CREATE TABLE `vendor_entity_locale` (
 ...
)