* Move push commits from models to modules/repository

* fix test

* fix test

* fix test

* fix test

* fix test

Co-authored-by: zeripath <art27@cantab.net>

* move transfer repository and rename repository on a service package and start action notification

* remove unused codes

* fix lint

* fix bugs

* fix test

* fix test

* fix test

* fix lint

* update go mod and sum

* move git diff codes from models to services/gitdiff

* fix template

* fix test

* fix template

* add migrations

* fix package dependency

* fix lints

* implements migrations except pull requests

* add releases

* migrating releases

* fix bug

* fix lint

* fix migrate releases

* fix tests

* add rollback

* pull request migtations

* fix import

* fix go module vendor

* add tests for upload to gitea

* more migrate options

* fix swagger-check

* fix misspell

* add options on migration UI

* fix log error

* improve UI options on migrating

* add support for username password when migrating from github

* fix tests

* remove comments and fix migrate limitation

* improve error handles

* migrate API will also support migrate milestones/labels/issues/pulls/releases

* fix tests and remove unused codes

* add DownloaderFactory and docs about how to create a new Downloader

* fix misspell

* fix migration docs

* Add hints about migrate options on migration page

* fix tests

* Fix counts on issues dashboard

* setupSess -> setupSession

* Unit test

* Load repo owners for issues