Remove Spring as Dependency

[Weltraumschaf]

We use Spring to make HTTP requests. This is a bit of bloat, since we use nothing else from Spring. Also the current 5.x has vulns and upgrading to 6.x breaks the code. Instead of fixing the breaking code from upgrade to Spring 6 we can also use the time to use a more light weight library for HTTP requests.

[Weltraumschaf]

Alternative libs:

• https://hc.apache.org/
  • Are we using in combination with Spring Boot
• https://mizosoft.github.io/methanol/
  • Only maintained by one person.
  • Last release over 1 year ago.
• https://github.com/AsyncHttpClient/async-http-client
  • does not use Semver deliberately
  • Async w/ Futures -> wil intorduce unnecessary complexity
• https://github.com/googleapis/google-http-java-client
  • TODO
• https://eclipse-ee4j.github.io/jersey/
  • TODO

[Weltraumschaf]

Maybe we do not need an library for that: https://medium.com/@Dracontis/sending-multipart-form-data-with-kotlin-and-java-11-httpclient-ebe53a17a0a8

Do it by hand: https://stackoverflow.com/questions/46392160/java-9-httpclient-send-a-multipart-form-data-request