fix(csharp/test/Drivers/Databricks): Enrich RetryHttpHandler with other status codes

[alexguo-db]

Follow up of #3177 (comment)

Proposed Changes

• Added support for additional HTTP status codes: 408 (Request Timeout), 502 (Bad Gateway), and 504 (Gateway Timeout), in addition to the existing 503 (Service Unavailable)
• Implemented exponential backoff with jitter when no Retry-After header is present

Testing

Unit tests
dotnet test --filter "FullyQualifiedName~RetryHttpHandlerTest"

[xUnit.net 00:00:00.00] xUnit.net VSTest Adapter v3.1.1+bf6400fd51 (64-bit .NET 8.0.7)
[xUnit.net 00:00:00.06]   Discovering: Apache.Arrow.Adbc.Tests.Drivers.Databricks
[xUnit.net 00:00:00.15]   Discovered:  Apache.Arrow.Adbc.Tests.Drivers.Databricks
[xUnit.net 00:00:00.16]   Starting:    Apache.Arrow.Adbc.Tests.Drivers.Databricks
[xUnit.net 00:00:25.28]   Finished:    Apache.Arrow.Adbc.Tests.Drivers.Databricks
  Apache.Arrow.Adbc.Tests.Drivers.Databricks test net8.0 succeeded (26.2s)

Test summary: total: 14, failed: 0, succeeded: 14, skipped: 0, duration: 26.2s
Build succeeded in 30.3s