refactor: migrate to latest gorm version

refactor: language mappings implementation

models/language_mapping.go

@@ -0,0 +1,17 @@
+package models
+
+type LanguageMapping struct {
+	ID        uint   `json:"id" gorm:"primary_key"`
+	User      *User  `json:"-" gorm:"not null"`
+	UserID    string `json:"-" gorm:"not null; index:idx_language_mapping_user; uniqueIndex:idx_language_mapping_composite"`
+	Extension string `json:"extension" gorm:"uniqueIndex:idx_language_mapping_composite"`
+	Language  string `json:"language"`
+}
+
+func validateLanguage(language string) bool {
+	return len(language) >= 1
+}
+
+func validateExtension(extension string) bool {
+	return len(extension) >= 1
+}