Add Iceberg REST auth server configuration property

[kiersten-stokes]

Description

This PR adds a new configuration property for an OAUTH2 server uri: iceberg.rest.auth.oauth2.uri

Motivation and Context

Fixes #23491

See linked issue for context

Impact

Adds a iceberg.rest.auth.oauth2.uri configurable property

Test Plan

Configuration tests have been updated

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• Please make sure your submission complies with our development, formatting, commit message, and attribution guidelines.
• PR description addresses the issue accurately and concisely. If the change is non-trivial, a GitHub Issue is referenced.
• Documented new properties (with its default value), SQL syntax, functions, or other functionality.
• If release notes are required, they follow the release notes guidelines.
• Adequate tests were added if applicable.
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Release Notes

Please follow release notes guidelines and fill in the release notes below.

== RELEASE NOTES ==

Iceberg Connector Changes
* Add iceberg.rest.auth.oauth2.uri configurable property :pr:`23739` 

[steveburnett]

LGTM! (docs)

Pull branch, local doc build, looks good. Thanks!

[agrawalreetika]

LGTM

[ZacBlanco]

It would be good to see a unit test where we can verify the catalog config has properly set the OAUTH2_SERVER_URI as well.

[prestodb-ci]

Saved that user @kiersten-stokes is from IBM

[steveburnett]

Formatting nit for the release note entry

== RELEASE NOTES ==

Iceberg Connector Changes
* Add ``iceberg.rest.auth.oauth2.uri`` configurable property. :pr:`23739` 

[steveburnett]

LGTM! (docs)

Pull branch, local doc build, looks good.