Add all pods view to logs explorer

What does this MR do?

Issue referencing this new filter #39165 (closed)

pod_name becomes a required argument for the kubernetes backend only.

returns pod names with the log messages and timestamp to add a new column in the UI

Additionally this fixes a couple of behaviour issues with the pod dropdown, namely what happens when the state is still loading, and when the user switches environments

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team