Make select jsinspector implementation headers private (#58943)

[coado]

Summary:

Mark the following jsinspector-modern headers as private instead of for-frameworks. All of them are implementation details of the inspector, and no for-frameworks header includes them:

• ConsoleTask, ConsoleTaskContext and ConsoleTaskOrchestrator implement console.createTask(): the task object, the context that captures the stack trace when a task is created, and the singleton that tracks which task is currently running. They are only used by the inspector's console sources, a console test, and PerformanceEntryReporter.cpp, which reads the current task from the orchestrator.
• EmulationAgent handles the CDP Emulation domain. It is only used by EmulationAgent.cpp and HostAgent.cpp.
• FallbackRuntimeAgentDelegate answers CDP requests for a JavaScript runtime that does not support debugging. It is only used by FallbackRuntimeAgentDelegate.cpp and FallbackRuntimeTargetDelegate.cpp. FallbackRuntimeTargetDelegate.h, which creates it, stays for-frameworks.
• InspectorPackagerConnectionImpl.h defines InspectorPackagerConnection::Impl, the hidden implementation of the inspector-proxy protocol. InspectorPackagerConnection.h only forward-declares it, and it is only used by InspectorPackagerConnection.cpp. InspectorPackagerConnection.h and WebSocketInterfaces.h stay for-frameworks, because each platform implements InspectorPackagerConnectionDelegate.
• RuntimeTargetGlobalStateObserver installs a JavaScript global that reports a boolean state, such as whether a debugger session is active, and notifies its subscribers when the state changes. RuntimeTargetTracingStateObserver uses it to report whether tracing is active. Both are only used by the RuntimeTarget sources and their own sources.
• Utf8.h provides truncateToValidUTF8, which trims a byte buffer so it does not end in the middle of a UTF-8 code point when IO.read slices a network resource. It is only used by NetworkIOAgent.cpp and its own unit test.
• ExecutionContextManager allocates execution context IDs. It is only created by HostTarget.cpp and used by InstanceTarget.cpp. HostTarget.h and InstanceTarget.h only hold it through std::shared_ptr, so they now forward-declare it instead of including the header, and the two sources include it directly.

React Native's own targets define RN_BUILDING, so the private guard does not affect them.

Changelog: [Internal]

Differential Revision: D123009197

[meta-codesync]

@coado has exported this pull request. If you are a Meta employee, you can view the originating Diff in D123009197.