feat: integration test (#770)

* feat: add insert test cases

* fix: update results after rebase develop

* feat: supports unsigned integer types and big_insert test

* test: add insert_invalid test

* feat: supports time index constraint for bigint type

* chore: time index column at last

* test: adds more order, limit test

* fix: style

* feat: adds numbers table in standable memory catalog mode

* feat: enable fail_fast and test_filter in sqlness

* feat: add more tests

* fix: test_filter

* test: add alter tests

* feat: supports if_not_exists when create database

* test: filter_push_down and catalog test

* fix: compile error

* fix: delete output file

* chore: ignore integration test output in git

* test: update all integration test results

* fix: by code review

* chore: revert .gitignore

* feat: sort the show tables/databases results

* chore: remove issue link

* fix: compile error and code format after rebase

* test: update all integration test results

src/api/greptime/v1/ddl.proto

@@ -50,6 +50,7 @@ message DropTableExpr {
 message CreateDatabaseExpr {
   //TODO(hl): maybe rename to schema_name?
   string database_name = 1;
+  bool create_if_not_exists = 2;
 }
 
 message AddColumns {