MM-57913 Increase maximum length of Preferences.Value column (#27297)

* MM-57913 Increase maximum length of Preferences.Value column

* Add missing column name to migration

* Lowercased table and column names

server/public/model/preference.go

@@ -60,6 +60,8 @@ const (
 	PreferenceEmailIntervalHour              = "hour"
 	PreferenceEmailIntervalHourAsSeconds     = "3600"
 	PreferenceCloudUserEphemeralInfo         = "cloud_user_ephemeral_info"
+
+	MaxPreferenceValueLength = 20000
 )
 
 type Preference struct {
@@ -84,7 +86,7 @@ func (o *Preference) IsValid() *AppError {
 		return NewAppError("Preference.IsValid", "model.preference.is_valid.name.app_error", nil, "name="+o.Name, http.StatusBadRequest)
 	}
 
-	if utf8.RuneCountInString(o.Value) > 2000 {
+	if utf8.RuneCountInString(o.Value) > MaxPreferenceValueLength {
 		return NewAppError("Preference.IsValid", "model.preference.is_valid.value.app_error", nil, "value="+o.Value, http.StatusBadRequest)
 	}