refactor.解耦关卡掉落相关任务，插件化

src/MeoAssistant/AbstractTaskPlugin.cpp

@@ -0,0 +1,26 @@
+#include "AbstractTaskPlugin.h"
+
+int asst::AbstractTaskPlugin::priority() const
+{
+    return m_priority;
+}
+
+bool asst::AbstractTaskPlugin::block() const
+{
+    return m_block;
+}
+
+void asst::AbstractTaskPlugin::set_priority(int priority)
+{
+    m_priority = priority;
+}
+
+void asst::AbstractTaskPlugin::set_block(bool block)
+{
+    m_block = block;
+}
+
+void asst::AbstractTaskPlugin::set_plugin_exit_flag(bool* exit_flag) noexcept
+{
+    AbstractTask::set_exit_flag(exit_flag);
+}