Use Quarkus Rest Client instead of splunk-library-javalogging

[vietk]

Quarkus logging splunk is using splunk-library-logging third party to reach the Splunk Event collector.

The idea is to replace this dependency by a Quarkus dedicated Rest Client for :

• Performance/troubleshotting reason (Performance issue when using json mode splunk/splunk-library-javalogging#257, Potential memory issues when slow HEC responses #255)
• Unifying the HTTP client (Splunk's Library is using ok http)
• Slow release cycle/ project activity
• Event Collector REST API is public - https://docs.splunk.com/Documentation/SplunkCloud/latest/Data/HECRESTendpoints
• Unnecessary logging system support provided (logback/log4j ... )
• No defined metrics and HTTP Client metrics produced