Include Proxy setting as part of deciding relativeURIs logic

[klustria]

Environment Details

• Helidon Version: Main
• Helidon NIMA

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Problem Description

#6803 added relativeURIs config to determine if relative or absolute URI will be used in the request as a feature parity with Helidon SE. However, proxy configuration also needs to be a factor in deciding on the form of URI to send. Particularly, when you use proxy, Helidon SE WebClient will use absolute URI in the request because of changes made in #2302 and #3438. The use of absolute URI was implemented because of section 5.1.2 Request-URI in https://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html which states:

The absoluteURI form is REQUIRED when the request is being made to a proxy.

Because of this, we need to replicate this behavior in Helidon NIMA. However, NIMA proxy implementation is still in the works in #6006, so this change will have to wait.

[klustria]

Since #6006 Nima: WebClient Proxy Support is a prerequisite of this change and that issue is slated for 4.0.0-M2, then I'm setting this to that milestone as well.

[klustria]

This will dealt with in PR #7425

[klustria]

PR #7425 is merged