Add description for AirbyteEstimateTraceMessage types (#19843)

* Add description for `AirbyteEstimateTraceMessage` types

* cleanup

* update python CDK docs too

airbyte-cdk/python/airbyte_cdk/models/airbyte_protocol.py

@@ -109,7 +109,11 @@ class Config:
         extra = Extra.allow
 
     name: str = Field(..., description="The name of the stream")
-    type: EstimateType = Field(..., description="The type of estimate", title="estimate type")
+    type: EstimateType = Field(
+        ...,
+        description="Estimates are either per-stream (STREAM) or for the entire sync (SYNC). STREAM is preferred, and requires the source to count how many records are about to be emitted per-stream (e.g. there will be 100 rows from this table emitted). For the rare source which cannot tell which stream a record belongs to before reading (e.g. CDC databases), SYNC estimates can be emitted. Sources should not emit both STREAM and SOURCE estimates within a sync.\n",
+        title="estimate type",
+    )
     namespace: Optional[str] = Field(None, description="The namespace of the stream")
     row_estimate: Optional[int] = Field(
         None,

airbyte-protocol/protocol-models/src/main/resources/airbyte_protocol/airbyte_protocol.yaml

@@ -217,7 +217,11 @@ definitions:
         type: string
       type:
         title: "estimate type" # this title is required to avoid python codegen conflicts with the "type" parameter in AirbyteMessage. See https://github.com/airbytehq/airbyte/pull/12581
-        description: The type of estimate
+        description: >
+          Estimates are either per-stream (STREAM) or for the entire sync (SYNC).
+          STREAM is preferred, and requires the source to count how many records are about to be emitted per-stream (e.g. there will be 100 rows from this table emitted).
+          For the rare source which cannot tell which stream a record belongs to before reading (e.g. CDC databases), SYNC estimates can be emitted.
+          Sources should not emit both STREAM and SOURCE estimates within a sync.
         type: string
         enum:
           - STREAM