Feature: #94577 - Clear indexed_search documents when content is changed

See Issue #94577

Description

A new Extension Configuration setting deleteFromIndexAfterEditing has been added to the extension indexed_search.

If enabled and a page or its content is edited, DataHandler triggers a hook to remove the page and its content from the search index.

Impact

A separate index and clearing it is always a tradeoff between having wrong content and no content in the search result. The index is filled by website visitors or bots calling the page in the frontend or by using the 3rd party extension crawler.

If the setting is enabled and the page is not yet re-indexed, no content will be shown in the search result, no matter if the editor just fixed one tiny typo in a content element.

If the feature flag is disabled, the editor needs to manually clear the index.