Move to ADv2 and update log configs

[JacksonDavenport]

What does this PR do?

This PR changes a few things:

• For customizing the Data Plane portion of the integration, points to the Integration docs for creating the custom integration file rather than creating some file on the host
• Moved to Autodiscovery V2 syntax for the Control Plane check
• Specifies the containers directly in the annotations (discovery and istio-proxy) as these should be pretty static and just remove that lookup step
• Update the log sections
  • The istiod logs are now formatted a bit differently than before, the original docs and linked are outdated relative to that pre 1.5 setup -> "[12]: https://istio.io/v1.4/docs/tasks/observability/logs/collecting-logs/"
  • The istio-proxy logs can be captured like normal, but for the Envoy Access Logs changed around to (1) enable it (2) update the configs as this doesn't require any special pathing

Motivation

Clean up a few config options

Additional Notes

The current source:istio Log Pipeline we have is a bit out of date relative to the current istiod log format.

Envoy Access Logs: https://istio.io/latest/docs/tasks/observability/logs/access-log/ The pre-existing source:envoy log pipeline captures most of the Istio/envoy access logs out-of-box. However, I did notice a few that didn't parse, although this may have to do with the Istio tracing my sandbox was using.

Review checklist (to be filled by reviewers)

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• [ ] Changelog entries must be created for modifications to shipped code
• [ ] Add the qa/skip-qa label if the PR doesn't need to be tested during QA.
• [ ] If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged

[JacksonDavenport]

Fixed merge conflicts, kept config file contents with respect to: https://github.com/DataDog/integrations-core/pull/18703