Create an interface for consuming data that fixes #5.

Create Consumer and ConsumerFactory traits.

Implement CDCRow struct that represents data passed to the consumer.

Implement CDCRowSchema that contains info about column order in the CDC table.

Create tests for Consumer module.

Author: procrastinationfighter

scylla-cdc/Cargo.toml

@@ -11,6 +11,8 @@ scylla = "0.3.0"
 tokio = { version = "1.1.0", features = ["rt", "io-util", "net", "time", "macros", "sync"] }
 chrono = "0.4.19"
 futures = "0.3.17"
+uuid = "0.8.2"
+num_enum = "0.5.4"
 
 [dev-dependencies]
 hex = "0.4.3"