feat: Initial support of postgresql wire protocol (#229)

* feat: initial commit of postgres protocol adapter

* initial commit of postgres server

* feat: use common_io runtime and correct testcase

* fix previous tests

* feat: adopt pgwire api changes and add support for text encoded data

* feat: initial integration with datanode

* test: add feature flag to test

* fix: resolve lint warnings

* feat: add postgres feature flags for datanode

* feat: add support for newly introduced timestamp type

* feat: adopt latest datanode changes

* fix: address clippy warning for flattern scenario

* fix: make clippy great again

* fix: address issues found in review

* chore: sort dependencies by name

* feat: adopt new Output api

* fix: return error on unsupported data types

* refactor: extract common code dealing with record batches

* fix: resolve clippy warnings

* test: adds some unit tests postgres handler

* test: correct test for cargo update

* fix: update query module name

* test: add assertion for error content

src/common/recordbatch/src/lib.rs

@@ -71,6 +71,7 @@ impl RecordBatches {
         self.schema.clone()
     }
 
+    // TODO: a new name that to avoid misunderstanding it as an allocation operation
     pub fn to_vec(self) -> Vec<RecordBatch> {
         self.batches
     }