v3.21.0

• Fixed gtrace tool generation code style bug with leading spaces
• Removed accounting load factor (unused field) in balancers
• Enabled by default anonymous credentials
• Enabled by default internal dns resolver
• Removed from defaults grpc.WithBlock() option
• Added ydb.Open method with required param connection string
• Marked ydb.New method as deprecated
• Removed package dsn
• Added sugar.DSN helper for make dsn (connection string)
• Refactored package retry (moved retryBackoff and retryMode implementations to internal)
• Refactored config.Config (remove interface Config, renamed private struct config to Config)
• Moved discovery/config to internal/discovery/config
• Moved coordination/config to internal/coordination/config
• Moved scheme/config to internal/scheme/config
• Moved scripting/config to internal/scripting/config
• Moved table/config to internal/table/config
• Moved ratelimiter/config to internal/ratelimiter/config

Full Changelog: v3.20.2...v3.21.0