Add support for right-aligned roomtext

This is mostly so people making levels in an RTL language have a more
pleasant and logical experience. If roomtext is placed in a level set
to RTL, it will get p1=1, which makes that roomtext right-aligned.
Because, imagine for English you click to place roomtext, and the text
runs left of where you clicked, which wouldn't be logical.

Since it's an entity-bound property, switching RTL on and off either in
the editor or via a script does not affect existing entities.

desktop_version/src/Graphics.cpp

@@ -3602,3 +3602,15 @@ void Graphics::render_roomname(uint32_t font_flag, const char* roomname, int r,
     font::print(font_flag | PR_CEN | PR_BOR | PR_CJK_LOW, -1, footerrect.y+1, roomname, r, g, b);
     set_blendmode(SDL_BLENDMODE_NONE);
 }
+
+void Graphics::print_roomtext(int x, const int y, const char* text, const bool rtl)
+{
+    uint32_t flags = PR_FONT_LEVEL | PR_CJK_LOW;
+
+    if (rtl)
+    {
+        flags |= PR_RIGHT;
+        x += 8; // the size of a tile, not font width!
+    }
+    font::print(flags, x, y, text, 196, 196, 255 - help.glow);
+}