[8.16](backport #4468) Update Logs Explorer docs with new summary column

[mergify]

Description

Adding the summary column removed the smart fields (except the actions smart field). I've removed the smart fields info from the docs. If we decided to cover the summary column, it should probably be in the discover docs as it applies to both Logs Explorer and Discover and we already defer to the Discover docs for most of the documents table.

I've also updated the screenshots to show the summary column.

Documentation sets edited in this PR

Check all that apply.

• Stateful (docs/en/observability/*)
• Serverless (docs/en/serverless/*)
• Integrations Developer Guide (docs/en/integrations/*)
• None of the above

Related issue

Closes #4317

Checklist

• Product/Engineering Review
• Writer Review

Follow-up tasks

Select one.

• This PR does not need to be ported to another doc set because:
  • The concepts in this PR only apply to one doc set (serverless or stateful)
  • The PR contains edits to both doc sets (serverless and stateful)
• This PR needs to be ported to another doc set:
  • Port to stateful docs: <link to PR or tracking issue>
  • Port to serverless docs: <link to PR or tracking issue>

---

This is an automatic backport of pull request #4468 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of bc7c5be has failed:

On branch mergify/bp/8.16/pr-4468
Your branch is up to date with 'origin/8.16'.

You are currently cherry-picking commit bc7c5be7.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   docs/en/observability/explore-logs.asciidoc
	modified:   docs/en/observability/images/log-explorer.png
	modified:   docs/en/observability/images/log-menu.png

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   docs/en/serverless/images/log-explorer.png
	deleted by us:   docs/en/serverless/images/log-menu.png
	deleted by us:   docs/en/serverless/logging/view-and-monitor-logs.asciidoc

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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