* 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
6543