* Save patches to temporary files

* Remove SavePatch and generate patches on the fly

* Use ioutil.TempDir

* fixup! Use ioutil.TempDir

* fixup! fixup! Use ioutil.TempDir

* RemoveAll LocalCopyPath() in initIntergrationTest

* Default to status checking on PR creation

* Remove unnecessary set to StatusChecking

* Protect against unable to load repo

* Handle conflicts

* Restore original conflict setting

* In TestPullRequests update status to StatusChecking before running TestPatch

* Move some pull request functions from models to services

* Fix test

In investigating #7947 it has become clear that the storage component of go-git repositories needs closing.

This PR adds this Close function and adds the Close functions as necessary.

In TransferOwnership the ctx.Repo.GitRepo is closed if it is open to help prevent the risk of multiple open files.

Fixes #7947

* Move pull webhook to notification

* fix fmt

* Rename HookQueue to hookQueue

* fix lint

* Move webhook to a standalone package under modules

* fix test

* fix comments

* Send email to assigned user

* Only send mail if enabled

* Mail also when assigned through API

* Need to refactor functions from models to issue service

* Refer to issue index rather than ID

* Disable email notifications completly at initalization if global disable

* Check of user enbled mail shall be in mail notification function only

* Initialize notifications from routers init function.

* Use the assigned comment when sending assigned mail

* Refactor so that assignees always added as separate step when new issue/pr.

* Check error from AddAssignees

* Check if user can be assiged to issue or pull request

* Missing return

* Refactor of CanBeAssigned check.

CanBeAssigned shall have same check as UI.

* Clarify function names (toggle rather than update/change), and clean up.

* Fix review comments.

* Flash error if assignees was not added when creating issue/pr

* Generate error if assignee users doesn't exist

* move AddTestPullRequestTask to pull service package from models

* fix fmt

* extract actions on new pull request from models to pulls service

* improve code

* move code.gitea.io/gitea/modules/pull to code.gitea.io/gitea/services/pull

* fix fmt

* Rename pulls.go to pull.go