MLE-23593 Using forked copy of Spring's deprecated OkHttp support

[rjrudin]

Spring's support for OkHttp has long been deprecated and will be removed in Spring 7. This copies the 4 necessary classes from Spring into our codebase so that we can keep using OkHttp without any deprecation warnings.

[github-actions]

Copyright Validation Results
Total: 9 | Passed: 8 | Failed: 0 | Skipped: 1 | at: 2025-09-19 15:26:50 UTC | commit: 1e1b140

⏭️ Skipped (Excluded) Files

• gradle.properties

✅ Valid Files

• ml-app-deployer/src/main/java/com/marklogic/appdeployer/command/AbstractCommand.java
• ml-app-deployer/src/main/java/com/marklogic/appdeployer/command/viewschemas/DeployViewSchemasCommand.java
• ml-app-deployer/src/main/java/com/marklogic/mgmt/ManageClient.java
• ml-app-deployer/src/main/java/com/marklogic/rest/util/RestTemplateUtil.java
• ml-app-deployer/src/main/java/com/marklogic/rest/util/vendor/AbstractStreamingClientHttpRequest.java
• ml-app-deployer/src/main/java/com/marklogic/rest/util/vendor/OkHttpClientHttpRequest.java
• ml-app-deployer/src/main/java/com/marklogic/rest/util/vendor/OkHttpClientHttpRequestFactory.java
• ml-app-deployer/src/main/java/com/marklogic/rest/util/vendor/OkHttpClientHttpResponse.java

✅ All files have valid copyright headers!