[FEATURE REQUEST] Refactor usage of DropwizardAppExtension in the tests for PolarisApplication to maximize the reuse

### Is your feature request related to a problem? Please describe.

There are a lot of tests uses DropwizardAppExtension to init a PolarisApplication, for example:
```
private static final DropwizardAppExtension EXT =
new DropwizardAppExtension<>(
PolarisApplication.class,
ResourceHelpers.resourceFilePath("polaris-server-integrationtest.yml"),
// Bind to random port to support parallelism
ConfigOverride.config("server.applicationConnectors[0].port", "0"),
ConfigOverride.config("server.adminConnectors[0].port", "0"),
// Block overlapping catalog paths:
ConfigOverride.config("featureConfiguration.ALLOW_OVERLAPPING_CATALOG_URLS", "false"));
```
in PolarisOverlappingCatalogTest.java.

### Describe the solution you'd like

We can refactor the usaage as a util function or base class for maximize reuse.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start with PolarisOverlappingCatalogTest.java and its DropwizardAppExtension setup, then search the PolarisApplication tests for similar initialization. Compare the repeated configuration before choosing a reusable utility function or base class. Done means the duplicated setup is consolidated and the affected tests still pass.

Written by the indexing model from the issue text.