Add date_created Field to Entity and Display in Metadata Component

[ayanaar]

Fix #2903

This pull request introduces a new date_created attribute to the Entity type and displays this date in the Metadata component in a human-readable format.

Key changes:

• date_created attribute is added to the Entity type.
• The Metadata component now includes a new EntityCreatedDate function that displays the creation date of the entity.
• The map_entities function now includes date_created as a datetime object.
• Corresponding tests in test_entity.py have been adjusted to reflect the changes in map_entities.