Broker extensions to provide operators of enterprise-wide clusters better control and flexibility

**Is your feature request related to a problem? Please describe.**
The central messaging platform at Intuit uses Apache Pulsar. The platform team operates multiple clusters that are used by hundreds of teams across Intuit. For complete visibility and to better serve customers, the platform needs the ability to intercept all key broker and ledger events. Also needed is the ability to transparently control the format of messages that get persisted in the disk store

**Describe the solution you'd like**
Would like to propose the following solution
* Extend the existing interface org.apache.pulsar.broker.intercept.BrokerInterceptor to support more granular events with all relevant context information
* Support a new interface to allow interception of write and read operations of a managed ledger and modify the payload
* Support dynamic load of managed ledger interceptor implementations similar to 'brokerEntryMetadataInterceptors'

**Describe alternatives you've considered**
The existing API 'onPulsarCommand' in BrokerInterceptor doesn't have enough context information for traceability

**Additional context**
None