Updated documentation to describe when validators run

[ruthst00]

Fixes #1161

Solution

The documentation has been updated in two files to resolve GitHub issue DATAREST-789 (#1161):

src/main/antora/modules/ROOT/pages/events.adoc — Added a new "Event Lifecycle and Object State" section that:

• Documents step-by-step when each event fires for POST, PUT, PATCH, DELETE, and association resource operations
• Explicitly calls out the critical PATCH behavior: BeforeSaveEvent receives the already-merged domain object (existing entity + patch applied), not the raw partial input
• Includes a summary reference table mapping each event to its triggering HTTP method and the object state passed to the handler
• Adds an inline comment in the annotated handler code example clarifying the PATCH object state

src/main/antora/modules/ROOT/pages/validation.adoc — Added a new "Validation Events and Object State" section that:

• Provides a reference table mapping each event prefix (e.g., beforeSave, beforeCreate) to its HTTP trigger and the object state the validator receives
• Adds a dedicated "Validation and PATCH Requests" subsection explicitly explaining that beforeSave validators receive the fully-merged entity for PATCH (not a partial object), with a concrete code example showing it is safe to validate all fields
• Expands the bean name wiring section with explicit examples for both beforeCreate and beforeSave validators
• Adds a cross-reference to the Events page for the full lifecycle details

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