SQL Expressions: Improve response to frame conversion handling (#100625)

- use types.Convert to get a more normalized type returned from GMS. After syncing with GMS maintainers, the underlying type of the row could be different things (e.g. int when unit32, so this calls the Convert method from the GMS types library to normalize the interface.
- Clean up fieldValFromRow more
- Use IsText to capture different string types
- Add more types to test, also update test to use same cmp.Diff method as others

---------

Co-authored-by: Sam Jewell <2903904+samjewell@users.noreply.github.com>

pkg/expr/sql/frame_table.go

@@ -3,10 +3,12 @@
 package sql
 
 import (
+	"fmt"
 	"io"
 	"strings"
 
 	mysql "github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/types"
 	"github.com/grafana/grafana-plugin-sdk-go/data"
 )
 
@@ -124,3 +126,38 @@ type partition []byte
 func (p partition) Key() []byte {
 	return p
 }
+
+// Helper function to convert data.FieldType to types.Type
+func convertDataType(fieldType data.FieldType) mysql.Type {
+	switch fieldType {
+	case data.FieldTypeInt8, data.FieldTypeNullableInt8:
+		return types.Int8
+	case data.FieldTypeUint8, data.FieldTypeNullableUint8:
+		return types.Uint8
+	case data.FieldTypeInt16, data.FieldTypeNullableInt16:
+		return types.Int16
+	case data.FieldTypeUint16, data.FieldTypeNullableUint16:
+		return types.Uint16
+	case data.FieldTypeInt32, data.FieldTypeNullableInt32:
+		return types.Int32
+	case data.FieldTypeUint32, data.FieldTypeNullableUint32:
+		return types.Uint32
+	case data.FieldTypeInt64, data.FieldTypeNullableInt64:
+		return types.Int64
+	case data.FieldTypeUint64, data.FieldTypeNullableUint64:
+		return types.Uint64
+	case data.FieldTypeFloat32, data.FieldTypeNullableFloat32:
+		return types.Float32
+	case data.FieldTypeFloat64, data.FieldTypeNullableFloat64:
+		return types.Float64
+	case data.FieldTypeString, data.FieldTypeNullableString:
+		return types.Text
+	case data.FieldTypeBool, data.FieldTypeNullableBool:
+		return types.Boolean
+	case data.FieldTypeTime, data.FieldTypeNullableTime:
+		return types.Timestamp
+	default:
+		fmt.Printf("------- Unsupported field type: %v", fieldType)
+		return types.JSON
+	}
+}