Rename Cookie Options to remove extra 'Cookie'

CHANGELOG.md

env_options.go

env_options_test.go

oauthproxy.go

oauthproxy_test.go

options.go

options_test.go

pkg/apis/options/cookie.go

pkg/cookies/cookies.go

pkg/sessions/cookie/session_store.go

pkg/sessions/redis/redis_store.go

pkg/sessions/session_store_test.go