Bugfix/field naming

[thanhpd56]

Fix 2 errors:
Error 1: When table is

Table districts {
  id bigint [pk, increment]
  code varchar(255) [not null, unique]
  name varchar(255)
  city_id bigint [ref: > cities.id, not null]
  my_city_id bigint [ref: > cities.id, not null]
  created_at datetime [not null, default: `CURRENT_TIMESTAMP`]
  updated_at datetime [not null, default: `CURRENT_TIMESTAMP`]

  Indexes {
    city_id [name: 'idx_districts_city_id']
  }
}

then the generated model contains 2 fields of Districts
After fix result will be:

// City is generated type for table 'cities'
type City struct {
	ID          int64      `json:"id" mapstructure:"id"`
	Districts   []District `gorm:"foreignkey:city_id"`
	MyDistricts []District `gorm:"foreignkey:my_city_id"`
	Name        *string    `json:"name" mapstructure:"name"`
	Code        string     `json:"code" mapstructure:"code"`
	CreatedAt   time.Time  `json:"created_at" mapstructure:"created_at"`
	UpdatedAt   time.Time  `json:"updated_at" mapstructure:"updated_at"`
}

Error 2:
Generate column search_text_v1 to SearchText field, so if table contains 2 fields of search_text_v1, and search_text_v2, the generated model will contain 2 fields SearchText.
After fix: search_text_v1 will generate SearchTextV1 field, search_text_v2 will generate SearchTextV2 field.