[DOCS] Update attributes and text references for Elastic Defend integration

[joepeeples]

Description

• Parent docs meta: [DOCS] [META] Rename integration to "Elastic Defend" #2463
• Related dev issue: https://github.com/elastic/security-team/issues/4759

Pending the new attribute created in elastic/docs#2516, we need to update all existing docs that reference the "Endpoint and Cloud Security" integration ({endpoint-cloud-sec}) to reference the new name and attribute: "Elastic Defend" and {elastic-defend}.

Important notes

• Although we recently cut down on hard-written references in the previous renaming in 8.3, it's still worthwhile to run a search for both attributes AND text using the old names.

• Merge changes into main and backport to 8.5. All docs prior to 8.5 will still reference the old attributes ({endpoint-cloud-sec} for 8.3 and 8.4, {endpoint-sec} for 8.2 and earlier).