978: remove spring-web

Ticket: planning#978 (closed)

• removed dependency
• added OkHttpClient
• created intermediate client to abstract between logic and HTTP handling
• adjusted and extended tests

pom.xml

@@ -77,7 +77,7 @@
         <junit.version>5.9.2</junit.version>
         <mockito.version>5.2.0</mockito.version>
         <junit-platform-version>1.9.2</junit-platform-version>
-        <mockito.version>5.3.0</mockito.version>
+        <mockito.version>5.3.1</mockito.version>
         <wiremock.version>2.27.2</wiremock.version>
         <hamcrest.version>1.3</hamcrest.version>
         <awaitility-version>4.2.0</awaitility-version>