Kill gorp (#19786)

* Kill gorp

Gorp is dead. Long live Gorp.

```release-note
NONE
```

store/sqlstore/adapters.go

@@ -6,17 +6,11 @@ package sqlstore
 import (
 	"bytes"
 	"database/sql/driver"
-	"encoding/json"
 	"fmt"
 	"strconv"
 	"strings"
 
-	"github.com/dyatlov/go-opengraph/opengraph"
-	"github.com/mattermost/gorp"
-	"github.com/mattermost/mattermost-server/v6/model"
-	"github.com/mattermost/mattermost-server/v6/shared/i18n"
 	"github.com/mattermost/mattermost-server/v6/shared/mlog"
-	"github.com/pkg/errors"
 )
 
 type jsonArray []string
@@ -68,85 +62,3 @@ func (t *TraceOnAdapter) Printf(format string, v ...interface{}) {
 type JSONSerializable interface {
 	ToJSON() string
 }
-
-type mattermConverter struct{}
-
-func (me mattermConverter) ToDb(val interface{}) (interface{}, error) {
-	switch t := val.(type) {
-	case model.StringMap:
-		return model.MapToJSON(t), nil
-	case map[string]string:
-		return model.MapToJSON(model.StringMap(t)), nil
-	case model.StringArray:
-		return model.ArrayToJSON(t), nil
-	case model.StringInterface:
-		return model.StringInterfaceToJSON(t), nil
-	case map[string]interface{}:
-		return model.StringInterfaceToJSON(model.StringInterface(t)), nil
-	case JSONSerializable:
-		return t.ToJSON(), nil
-	case *opengraph.OpenGraph:
-		return json.Marshal(t)
-	case *model.PostImage:
-		return json.Marshal(t)
-	}
-
-	return val, nil
-}
-
-func (me mattermConverter) FromDb(target interface{}) (gorp.CustomScanner, bool) {
-	switch target.(type) {
-	case *model.StringMap:
-		binder := func(holder, target interface{}) error {
-			s, ok := holder.(*string)
-			if !ok {
-				return errors.New(i18n.T("store.sql.convert_string_map"))
-			}
-			b := []byte(*s)
-			return json.Unmarshal(b, target)
-		}
-		return gorp.CustomScanner{Holder: new(string), Target: target, Binder: binder}, true
-	case *map[string]string:
-		binder := func(holder, target interface{}) error {
-			s, ok := holder.(*string)
-			if !ok {
-				return errors.New(i18n.T("store.sql.convert_string_map"))
-			}
-			b := []byte(*s)
-			return json.Unmarshal(b, target)
-		}
-		return gorp.CustomScanner{Holder: new(string), Target: target, Binder: binder}, true
-	case *model.StringArray:
-		binder := func(holder, target interface{}) error {
-			s, ok := holder.(*string)
-			if !ok {
-				return errors.New(i18n.T("store.sql.convert_string_array"))
-			}
-			b := []byte(*s)
-			return json.Unmarshal(b, target)
-		}
-		return gorp.CustomScanner{Holder: new(string), Target: target, Binder: binder}, true
-	case *model.StringInterface:
-		binder := func(holder, target interface{}) error {
-			s, ok := holder.(*string)
-			if !ok {
-				return errors.New(i18n.T("store.sql.convert_string_interface"))
-			}
-			b := []byte(*s)
-			return json.Unmarshal(b, target)
-		}
-		return gorp.CustomScanner{Holder: new(string), Target: target, Binder: binder}, true
-	case *map[string]interface{}:
-		binder := func(holder, target interface{}) error {
-			s, ok := holder.(*string)
-			if !ok {
-				return errors.New(i18n.T("store.sql.convert_string_interface"))
-			}
-			b := []byte(*s)
-			return json.Unmarshal(b, target)
-		}
-		return gorp.CustomScanner{Holder: new(string), Target: target, Binder: binder}, true
-	}
-
-	return gorp.CustomScanner{}, false
-}