feat: add page that shows transformation configuration

src/main/kotlin/dev/dnpm/etl/processor/services/TransformationService.kt

@@ -51,9 +51,13 @@ class TransformationService(private val objectMapper: ObjectMapper, private val
         return objectMapper.readValue(json, MtbFile::class.java)
     }
 
+    fun getTransformations(): List<Transformation> {
+        return this.transformations
+    }
+
 }
 
-class Transformation private constructor(internal val path: String) {
+class Transformation private constructor(val path: String) {
 
     lateinit var existingValue: Any
         private set

src/main/kotlin/dev/dnpm/etl/processor/web/TransformationController.kt

@@ -0,0 +1,41 @@
+/*
+ * This file is part of ETL-Processor
+ *
+ * Copyright (c) 2023  Comprehensive Cancer Center Mainfranken, Datenintegrationszentrum Philipps-Universität Marburg and Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package dev.dnpm.etl.processor.web
+
+import dev.dnpm.etl.processor.services.TransformationService
+import org.springframework.stereotype.Controller
+import org.springframework.ui.Model
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestMapping
+
+@Controller
+@RequestMapping(path = ["transformations"])
+class TransformationController(
+    private val transformationService: TransformationService
+) {
+
+    @GetMapping
+    fun index(model: Model): String {
+        model.addAttribute("transformations", transformationService.getTransformations())
+
+        return "transformations"
+    }
+
+}