fix(healthcare): don't store DICOM instance before each DICOMweb test

[noerog]

Description

Only store DICOM instance once for all DICOMweb tests. Previously, storing a duplicate instance returned a 200, but it now returns a 409, causing tests to fail.

The JUnit4 MethodSorters (https://junit.org/junit4/javadoc/4.12/org/junit/runners/MethodSorters.html) functionality is also incorrectly running the DicomWebDeleteStudy test too early, even though its name was modified so that it ran last in the NAME_ASCENDING order, so update each test's name to ensure that they run in order.

Fixes

• 9266

• 9265

• 9264

• 9263

• 9262

• 9261

Checklist

• [X] I have followed Sample Format Guide
• [X] pom.xml parent set to latest shared-configuration
• [] Appropriate changes to README are included in PR
• [ ] These samples need a new API enabled in testing projects to pass (let us know which ones)
• [ ] These samples need a new/updated env vars in testing projects set to pass (let us know which ones)
• [X] Tests pass: mvn clean verify required
• [X] Lint passes: mvn -P lint checkstyle:check required
• [ ] Static Analysis: mvn -P lint clean compile pmd:cpd-check spotbugs:check advisory only
• [ ] This sample adds a new sample directory, and I updated the CODEOWNERS file with the codeowners for this sample
• [ ] This sample adds a new Product API, and I updated the Blunderbuss issue/PR auto-assigner with the codeowners for this sample
• [X] Please merge this PR for me once it is approved