[lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)

This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h

@@ -77,34 +77,9 @@ public:
   StructuredData::GenericSP
   CreateScriptCommandObject(const char *class_name) override;
 
-  StructuredData::ObjectSP
-  CreateScriptedThreadPlan(const char *class_name,
-                           const StructuredDataImpl &args_data,
-                           std::string &error_str,
-                           lldb::ThreadPlanSP thread_plan) override;
-
   StructuredData::ObjectSP
   CreateStructuredDataFromScriptObject(ScriptObject obj) override;
 
-  bool ScriptedThreadPlanExplainsStop(StructuredData::ObjectSP implementor_sp,
-                                      Event *event,
-                                      bool &script_error) override;
-
-  bool ScriptedThreadPlanShouldStop(StructuredData::ObjectSP implementor_sp,
-                                    Event *event, bool &script_error) override;
-
-  bool ScriptedThreadPlanIsStale(StructuredData::ObjectSP implementor_sp,
-                                 bool &script_error) override;
-
-  lldb::StateType
-  ScriptedThreadPlanGetRunState(StructuredData::ObjectSP implementor_sp,
-                                bool &script_error) override;
-
-  bool
-  ScriptedThreadPlanGetStopDescription(StructuredData::ObjectSP implementor_sp,
-                                lldb_private::Stream *s,
-                                bool &script_error) override;
-
   StructuredData::GenericSP
   CreateScriptedBreakpointResolver(const char *class_name,
                                    const StructuredDataImpl &args_data,
@@ -136,6 +111,9 @@ public:
 
   lldb::ScriptedThreadInterfaceSP CreateScriptedThreadInterface() override;
 
+  lldb::ScriptedThreadPlanInterfaceSP
+  CreateScriptedThreadPlanInterface() override;
+
   lldb::OperatingSystemInterfaceSP CreateOperatingSystemInterface() override;
 
   StructuredData::ObjectSP