Make history file path configurable

- UserConfigPathProvider interface to provid "user-level"
  config directory which can be used within a shell.
- New options which can be used to configure behaviour.
  spring.shell.history.enabled
  spring.shell.history.name
  spring.shell.config.location
  spring.shell.config.env
- Fixes #417

spring-shell-core/src/main/java/org/springframework/shell/config/UserConfigPathProvider.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.shell.config;
+
+import java.nio.file.Path;
+
+/**
+ * Interface providing a {@link Path} to a location where
+ * user level runtime configuration files are strored.
+ *
+ * @author Janne Valkealahti
+ */
+@FunctionalInterface
+public interface UserConfigPathProvider {
+
+	/**
+	 * Provides a path to a user config location.
+	 *
+	 * @return a path to user config location
+	 */
+	Path provide();
+}