Make Projects Individually Runnable

- This is important for running a project from an isolated directory
- It also helps the IDE to correctly download sources when debugging
a project

servlet/spring-boot/java/data/gradle/libs.versions.toml

@@ -0,0 +1 @@
+../../../../../gradle/libs.versions.toml

servlet/spring-boot/java/data/settings.gradle

@@ -0,0 +1,8 @@
+pluginManagement {
+    repositories {
+        mavenCentral()
+        gradlePluginPortal()
+        maven { url 'https://repo.spring.io/milestone' }
+        maven { url "https://repo.spring.io/snapshot" }
+    }
+}