[fix][broker] Read subscription properties directly from cursor

[nodece]

Motivation

PersistentSubscription.subscriptionProperties stores a cached snapshot initialized on construction, and can only be refreshed via updateSubscriptionProperties.

Other components write properties directly using ManagedCursor.putCursorProperty, especially the #pulsar.internal.delayed.bucket_* keys generated by the delayed message bucket tracker, but these changes will not sync to the local cache.

This leads to stale data returned by:

• org.apache.pulsar.client.admin.Topics#getSubscriptionProperties
• org.apache.pulsar.client.admin.Topics#getStats(java.lang.String, org.apache.pulsar.client.admin.GetStatsOptions)

The cache can only reload the latest data from cursor.getCursorProperties() after broker restart.

Modifications

• Remove cached subscriptionProperties field, use cursor as the single source of truth for properties.
• Modify getSubscriptionProperties() to directly return cursor.getCursorProperties(), so admin interfaces and PersistentSubscription.getStatsAsync can read real-time data.
• Simplify updateSubscriptionProperties to one single cursor.setCursorProperties(...) call, no extra cache field synchronization required.
• Deprecate the constructor overload with subscriptionProperties parameter. This unused parameter will be deleted in a subsequent PR after cleaning all relevant callsites in PersistentTopic.
• Add unit test PersistentSubscriptionTest#testGetSubscriptionPropertiesReflectsLiveCursorUpdates to verify real-time property visibility for both getSubscriptionProperties() and stats logic.