feat: introduce CDC write-side support for the Update operations

This change introduces a `CDCTracker` which helps collect changes during
merges and update. This is admittedly rather inefficient, but my hope is
that this provides a place to start iterating and improving upon the
writer code

There is still additional work which needs to be done to handle table
features properly for other code paths (see the middleware discussion we
have had in Slack) but this produces CDC files for Update operations

Fixes #604
Fixes #2095

crates/core/Cargo.toml

@@ -115,7 +115,8 @@ tokio = { version = "1", features = ["macros", "rt-multi-thread"] }
 utime = "0.3"
 
 [features]
-default = []
+cdf = []
+default = ["cdf"]
 datafusion = [
     "dep:datafusion",
     "datafusion-expr",

crates/core/src/delta_datafusion/mod.rs

@@ -509,6 +509,12 @@ impl<'a> DeltaScanBuilder<'a> {
         self
     }
 
+    /// Use the provided [SchemaRef] for the [DeltaScan]
+    pub fn with_schema(mut self, schema: SchemaRef) -> Self {
+        self.schema = Some(schema);
+        self
+    }
+
     pub async fn build(self) -> DeltaResult<DeltaScan> {
         let config = self.config;
         let schema = match self.schema {