[FEATURE] Alter language table [icon, is_default] and insert languages

[hamidsultanzadeh]

• alter language table and add new columns [icon (will store path), is_default] The last version of the migration file is commented on here https://github.com/webperside/course-erp-backend/issues/58 name: alter_language_is_default don't forget to put the last version on https://github.com/webperside/course-erp-backend/issues/58 Source branch: main
• create a new folder inside migrations named staticdata name of this migration file will be SD1-language-data insert the following rows [ name ][ is_default][ icon ] [ lang_az ][ 1 ][ lang_az ] [ lang_en ][ 0 ][ lang_en ] [ lang_ru ][ 0 ][ lang_ru ]
• be sure that you updated the service method for this changes [use this columns on methods]
• create new method inside language service which returns default language (is_default = 1) (there is always one row, don't use list for it)