SNOW-1044219: Add marker annotation for internal API (#1629)

Author: sfc-gh-dprzybysz

src/main/java/net/snowflake/client/core/SnowflakeJdbcInternalApi.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2024 Snowflake Computing Inc. All right reserved.
+ */
+package net.snowflake.client.core;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Elements marked with this annotation should be considered as internal API even if they are public
+ */
+@Target({
+  ElementType.PACKAGE,
+  ElementType.TYPE,
+  ElementType.FIELD,
+  ElementType.CONSTRUCTOR,
+  ElementType.METHOD
+})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface SnowflakeJdbcInternalApi {}