feat(zns-importer): add ZNSImportService with tests and REST controller

- Created `ZnsImportService` to handle uploading, parsing, and persisting ZNS data from legacy `.zip` files.
- Introduced corresponding test cases in `ZnsImportServiceTest` for handling edge cases including imports and updates.
- Added REST controller `ZnsImportController` for initiating import jobs and retrieving their status.
- Defined `ZnsImportResult` data structure for reporting results of import operations.
- Established database configuration specific to ZNS importer for development profile.
- Updated utility libraries with `FixedWidthLineReader` for fixed-width string parsing.
- Refactored architecture by placing parser logic in `core:zns-parser` for reuse across backend and Compose Desktop app.

Signed-off-by: Stefan Mogeritsch <stefan.mo.co@gmail.com>

backend/infrastructure/zns-importer/build.gradle.kts

@@ -0,0 +1,16 @@
+plugins {
+  alias(libs.plugins.kotlinJvm)
+}
+
+dependencies {
+  implementation(platform(projects.platform.platformBom))
+  implementation(projects.core.coreUtils)
+  implementation(projects.core.coreDomain)
+  implementation(projects.core.znsParser)
+  implementation(projects.backend.services.clubs.clubsDomain)
+  implementation(projects.backend.services.persons.personsDomain)
+  implementation(projects.backend.services.horses.horsesDomain)
+  implementation(projects.backend.services.officials.officialsDomain)
+
+  testImplementation(projects.platform.platformTesting)
+}