Create `OnEmit` for simple processor implementation of `LogRecordProcessor`

[kmos]

Scope

Processors are responsible for batching and conversion of LogRecords to exportable representation and passing to exporters. LogRecordProcessors can be registered directly on SDK LoggerProvider and they are invoked in the same order as they were registered. Each processor registered on LoggerProvider is part of a pipeline that consists of a processor and optional exporter. The SDK MUST allow each pipeline to end with an individual exporter:

  +-----+------------------------+   +------------------------------+   +-------------------------+
  |     |                        |   |                              |   |                         |
  |     |                        |   | Batching LogRecordProcessor  |   |    LogRecordExporter    |
  |     |                        +---> Simple LogRecordProcessor    +--->     (OtlpExporter)      |
  |     |                        |   |                              |   |                         |
  | SDK | Logger.emit(LogRecord) |   +------------------------------+   +-------------------------+
  |     |                        |
  |     |                        |
  |     |                        |
  |     |                        |
  |     |                        |
  +-----+------------------------+

For a LogRecordProcessor registered directly on SDK LoggerProvider, the logRecord mutations MUST be visible in next registered processors.

OnEmit

OnEmit is called when a LogRecord is emitted. This method is called synchronously on the thread that emitted the LogRecord, therefore it SHOULD NOT block or throw exceptions.