OpenAPI 3.0.4: apply diff changes to documentation and completion rules

[char0n]

Currently we already use OpenAPI 3.0.4 spec authoritative links (https://spec.openapis.org/) inside apidom-ls rules, but the texts are still from OpenAPI 3.0.3. The goal of this issue is to apply the changes from OpenAPI 3.0.4 spec into our documentation and completion OpenAPI 3.0.x rules.

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Parent issue: #4612