Lunny Xiao e72acd5e5b Split migrations folder (#21549) ...

There are too many files in `models/migrations` folder so that I split
them into sub folders.

2022-11-02 16:54:36 +08:00

..

gitea-v1.6.4.mssql.sql.gz

…

gitea-v1.6.4.mysql.sql.gz

…

gitea-v1.6.4.postgres.sql.gz

…

gitea-v1.6.4.sqlite3.sql.gz

…

gitea-v1.7.0.mssql.sql.gz

…

gitea-v1.7.0.mysql.sql.gz

…

gitea-v1.7.0.postgres.sql.gz

…

gitea-v1.7.0.sqlite3.sql.gz

…

migration_test.go

…