overhauled API:

- wrote openapi schema
- re-implemented api endpoint following openapi schema
- intensified and improved working with Result objects

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

de.srsoftware.cal.app/build.gradle.kts

@@ -7,7 +7,7 @@ dependencies {
 
     implementation("de.srsoftware:configuration.api:1.0.0")
     implementation("de.srsoftware:configuration.json:1.0.0")
-    implementation("de.srsoftware:tools.http:1.0.4")
+    implementation("de.srsoftware:tools.http:1.2.1")
     implementation("de.srsoftware:tools.logging:1.0.2")
     implementation("de.srsoftware:tools.web:1.3.8")
     implementation("com.mysql:mysql-connector-j:9.1.0")