man: Update zpool-event subclass names and document new types

[yyhran]

Motivation and Context

The man page was incomplete and the documentation in the code was getting increasingly stale.

Description

This PR updates the zpool-events.8 man page to standardize the event subclass names and document new event types, ensuring the documentation is consistent with internal code.

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Quality assurance (non-breaking change which makes the code more robust against bugs)
• Breaking change (fix or feature that would cause existing functionality to change)
• Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the OpenZFS code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• I have run the ZFS Test Suite with this change applied.
• All commit messages are properly formatted and contain Signed-off-by.

[behlendorf]

Thanks for the documentation refresh. These clearly haven't been carefully reviewed in a quite while. While you're here can you add these additional missing subclasses.

authentication - Issued when there is a decryption / authentication error.
pool_create - Issued when a pool is created.
config_cache_write - Issued when the config cache file cannot be written.
vdev_add - Issued when a vdev is added to a pool.
vdev_attach - Issued when a vdev is attached to a mirror or raidz vdev type.
vdev_online - Issued when an offline vdev is brought online.
history_event - Issued when a message is added to the internal history log.
bootfs_vdev_attach - Issued when a vdev is attached to a root pool with the bootfs property set.

And you'll also need to resolve the CI checkstyle failure.

[behlendorf]

Suggested change

	.It Sy trim_paused
	.It Sy trim_suspend

[yyhran]

Thank you for your additions and suggestions; the relevant changes have been committed.