OEL-1301: Move oe_content base fields into submodule

[GilNovacomm]

OEL-1301

Description

Move oe_content base fields into its own submodule.

QA notes

Clean install

Testing the update path

git checkout 2.x

./vendor/bin/run drupal:site-setup 
./vendor/bin/run drupal:site-install
./vendor/bin/drush uli

Go to /admin/reports/status and check that there are no Entity/Field Definitions mismatch errors.

Do a login for a test user and, in the node_field_data table, check that the base fields bellow are correctly filled.

git checkout OEL-1301
./vendor/bin/drush en oe_content_corporate_fields -y
./vendor/bin/drush updb -y
Refresh /admin/reports/status and check that there are no Entity/Field Definitions mismatch errors.

Check the users_field_data table. The fields should be filled with the previous data.