* Add repo-sync-releases admin command

Will help recovering corrupted database, see #3247

* Load repos in chunks of 10, exit with error if unable to get a list, scan private repos, fix typo

* Fix debug output about num releases

* Introduce RepositoryListDefaultPageSize constant, set to 64

Use it from the new admin command

* Use RepositoryListDefaultPageSize in more places

* Document RepositoryListDefaultPageSize

* Add repo type option to /api/repo/search

* Add tests and fix result of collaborative filter in specific condition

* Fix/optimize search & tests

* Improve integration tests

* Fix lint errors

* Fix unit tests

* Change and improve internal implementation of repo search

* Use NonexistentID

* Make search api more general

* Change mirror and fork search behaviour

* Fix tests & typo in comment

* Remove redudant functions and code

* Improve issue indexer

* Fix new issue sqlite bug

* Different test indexer paths for each db

* Add integration indexer paths to make clean

* Fix counts on issues dashboard

* setupSess -> setupSession

* Unit test

* Load repo owners for issues

* fix: Admin can see all private repositories on Explore page.

* refactor: fix session

use terms instead of fields as variable name to avoid confusion: NewPhraseQuery(terms []string, field string)