Refactor: Python 3.12, build libtcod & SFML from source. Cmake build. Directory cleanup

directories needed:
* build - for cmake output
* deps - stuff needed to compile McRogueface (headers)
	libtcod -> ../modules/libtcod/src/libtcod
	sfml -> ../modules/SFML/include/SFML
	python -> ../modules/cpython/Include
* lib - stuff needed to link McRogueFace (shared objects); also required at runtime
	libtcod -> `../modules/libtcod/buildsys/autotools/.libs/libtcod.so.1.0.24`
	sfml -> `../modules/SFML/build/lib/*`
	python -> `../modules/cpython/libpython3.12.so`; standard lib at ../modules/cpython/build/lib.linux-x86_64-3.12 & ../modules/cpython/Lib

You can get dependencies by:
 - Build from source (i.e. all submodules)
 - Go download them from each project's website
 - install packages from your distro and symlink them to deps/lib directories

src/Entity.cpp

@@ -0,0 +1,25 @@
+#include "Entity.h"
+
+Entity::Entity(const size_t i, const std::string & t)
+    : m_id(i), m_tag(t) {}
+
+bool Entity::isActive() const
+{
+    return m_active;
+}
+
+const std::string & Entity::tag() const
+{
+    return m_tag;
+}
+
+const size_t Entity::id() const
+{
+    return m_id;
+}
+
+void Entity::destroy()
+{
+    m_active = false;
+}
+