[Internal]: Update references to integration tiles UX

### Description

We're introducing an updated integration tiles navigation UX affecting integration-type and input-type (not content-type) packages. Documentation pages such as https://www.elastic.co/docs/reference/fleet/add-integration-to-policy should be reviewed and updated accordingly.

This new UX will impact Fleet's Integrations UI as well as integration tiles in Observability onboarding and Security onboarding pages.

This change targets 9.6.0.

Note that it is currently behind a disabled feature flag, there is a followup issue for enabling it: https://github.com/elastic/ingest-dev/issues/9416

### Resources

Main issue: https://github.com/elastic/ingest-dev/issues/7777
Implementation PR: https://github.com/elastic/kibana/pull/287384
Followup issue that will enable the feature: https://github.com/elastic/ingest-dev/issues/9416

### Which deployment methods does this change impact?

Elastic On-Prem and Cloud (all)

### Feature differences

Identical

### What Elastic Stack release is this request related to?

9.6

### Serverless release

_No response_

### Collaboration model

Unknown

### Point of contact.

**Main contact:** @jillguyonnet

**Stakeholders:** @elastic/streams-ui

Start with the linked add-integration-to-policy documentation page, then review the main issue and implementation PR for the updated integration tiles navigation. Check references for integration-type and input-type packages across Fleet, Observability onboarding, and Security onboarding, excluding content-type; done means the affected documentation matches the new UX before the feature is enabled.

Written by the indexing model from the issue text.