Fix gRPC communication with gzip compression for empty responses in .NET 9+

[qodo-code-review]

Description

• .NET 9+ GZipStream produces 0 bytes for empty responses, breaking gRPC communication when gzip compression is enabled
• Standard GZipStream does not write valid gzip header/footer for empty content, causing decompression failures
• Custom compression provider needed to handle edge case of empty response bodies

Deliverables

• Custom Provider: Implement GzipCompressionProvider with EmptyContentHandlingGzipStream that writes RFC 1952 compliant gzip format for empty content
• Test Coverage: Add comprehensive unit tests validating empty content handling on Dispose/Flush and non-empty round-trip compression
• Integration: Update gRPC compression configuration in API and cluster startup to use custom provider instead of default implementation

[linear]

DB-1806