Contexts update + buffer flushing + cleanup (#338)

* Update lib/rocprofiler-sdk/context/context.*

- get_registered_contexts functions (local copy)

* Update lib/rocprofiler-sdk/hsa/{queue,queue_controller}.cpp

- remove ROCPROFILER_BUFFER_TRACING_MEMORY_COPY code

* Update tests/kernel-tracing/kernel-tracing.cpp

- move stop() and flush() in tool_fini to before reporting of sizes of data collected

* Update lib/rocprofiler-sdk/hsa/hsa.*

- remove stale set_callback / activity_functor_t code

* Update lib/rocprofiler-sdk/buffer.cpp

- full wait instead of returning busy when buffer is busy
- use task_group::join instead of task_group::wait to fully wait for tasks to finish (bug fix)

* Update lib/rocprofiler-sdk/agent.cpp

- support agent mapping for CPU agents

* Remove direct access to vector of registered contexts

source/lib/rocprofiler-sdk/context.cpp

@@ -107,7 +107,7 @@ rocprofiler_context_is_valid(rocprofiler_context_id_t context_id, int* status)
     {
         if(itr && itr->context_idx == context_id.handle)
         {
-            auto _ret = rocprofiler::context::validate_context(itr.get());
+            auto _ret = rocprofiler::context::validate_context(itr);
             *status   = (_ret == ROCPROFILER_STATUS_SUCCESS) ? 1 : 0;
             return _ret;
         }