* use different structs for MigrateRepoOptions on UI and API

* Fix TokenAuth and rename UID to an understandable Name

* fix swagger doc

* simplify & mk redable

* R E F A C T O R:
migration has now internal 3 structs to store its options:
 * the Options for WebUI: modules/auth/repo_form.go
 * the Options for API: modules/structs/repo.go
 * the option struct with after validation for internal prossessing: modules/migrations/base/options.go

* Copyright Header

* Deprecate UID - add RepoOwner

* adopt repo.go -> migrate.go

* add comment about each struct purpose

* lint