Add tests for import structure and effect

Author: Pikachu920

src/main/java/org/skriptlang/reflect/java/elements/structures/StructImport.java

@@ -183,7 +183,7 @@ public static class EffImport extends Effect {
 
     @Override
     public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
-      if (!getParser().isCurrentEvent(EffectCommandEvent.class)) {
+      if (!getParser().isCurrentEvent(EffectCommandEvent.class) && !Skript.testing()) {
         Skript.error("The import effect can only be used in effect commands. " +
             "To use imports in scripts, use the section.");
         return false;

src/test/scripts/EffImport.sk

@@ -0,0 +1,3 @@
+test "import from effect":
+  import java.lang.Byte
+  assert Byte.SIZE is set with "Failed to use import from effect"

src/test/scripts/StructImport.sk

@@ -0,0 +1,8 @@
+import:
+  java.lang.Math
+  java.lang.Math as AliasForMath
+
+test "import from structure available":
+  assert Math.PI is set with "Failed to use import from structure"
+  assert AliasForMath.PI is set with "Failed to use import alias from structure"
+