* Add info about list endpoints to CONTRIBUTING.md
* Let all list endpoints return X-Total-Count header
* Add TODOs for GetCombinedCommitStatusByRef
* Fix models/issue_stopwatch.go
* Rrefactor models.ListDeployKeys
* Introduce helper func and use them for SetLinkHeader related func
* refactor routers directory
* move func used for web and api to common
* make corsHandler a function to prohibit side efects
* rm unused func
Co-authored-by: 6543 <6543@obermui.de>