[Enhance][Bug fix] Support skill_maya & World mode value display bug

- Add support for the skill 'skill_maya'
- Fix a bug that some characters' skill cannot display proper values in world mode progression
- Fix a bug that 'skill_mithra' results in adding `prog` value instead of world mode progress
- For Arcaea 4.7.0

latest version/database/init/tables.sql

@@ -69,6 +69,7 @@ level int,
 exp real,
 is_uncapped int,
 is_uncapped_override int,
+skill_flag int,
 primary key(user_id, character_id)
 );
 create table if not exists user_char_full(user_id int,
@@ -77,6 +78,7 @@ level int,
 exp real,
 is_uncapped int,
 is_uncapped_override int,
+skill_flag int,
 primary key(user_id, character_id)
 );
 create table if not exists character(character_id int primary key,