Add commands.getDimension()

Debated "commands.getBlockDimension()" instead, to match
getBlockPosition, but I think this is fine.

Fixes #1866.

projects/common/src/main/java/dan200/computercraft/shared/computer/apis/CommandAPI.java

@@ -157,6 +157,18 @@ public class CommandAPI implements ILuaAPI {
         return Collections.unmodifiableList(result);
     }
 
+    /**
+     * Get the name of the dimension the current command computer is in, such as {@code minecraft:overworld}.
+     *
+     * @return The dimension the computer is in.
+     * @see #getBlockPosition()
+     * @since 1.119.0
+     */
+    @LuaFunction
+    public final String getDimension() {
+        return computer.getLevel().dimension().location().toString();
+    }
+
     /**
      * Get the position of the current command computer.
      *
@@ -165,10 +177,10 @@ public class CommandAPI implements ILuaAPI {
      * @cc.treturn number This computer's y position.
      * @cc.treturn number This computer's z position.
      * @cc.see gps.locate To get the position of a non-command computer.
+     * @see #getDimension()
      */
     @LuaFunction
     public final Object[] getBlockPosition() {
-        // This is probably safe to do on the Lua thread. Probably.
         var pos = computer.getPosition();
         return new Object[]{ pos.getX(), pos.getY(), pos.getZ() };
     }