Make base_table and title required in ViewsWizard

Problem/Motivation

This is a followup from 📌 Convert ViewsWizard plugin discovery to attributes Active based on this comment

base_table is optional when there is a deriver and required if there isn't.

Steps to reproduce

Proposed resolution

Make base_table and possible title required in \Drupal\views\Attribute\ViewsWizard.
In \Drupal\views\Plugin\views\wizard\Standard set base_table to an empty string as it is derived. Title is required here because wizards are for the UI and this is used on the views add page.

Remaining tasks

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User interface changes

API changes

Data model changes

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