[IMP] administration: new db manager ui

[fw-bot]

Align the Odoo Online page with the new UI of the DB manager.

Forward-Port-Of: #15482
Forward-Port-Of: #15476

[robodoo]

[fw-bot]

@xpl-odoo cherrypicking of pull request #15476 failed.

stdout:

Auto-merging content/administration/odoo_online.rst
CONFLICT (content): Merge conflict in content/administration/odoo_online.rst
Auto-merging content/applications/studio/automated_actions/webhooks.rst

Either perform the forward-port manually (and push to this branch, proceeding as usual) or close this PR (maybe?).

In the former case, you may want to edit this PR message as well.

⚠️ after resolving this conflict, you will need to merge it via @robodoo.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port