Support unarchiving Metrics & Segments via the API [WIP]

src/metabase/api/common.clj

src/metabase/api/metric.clj

src/metabase/api/segment.clj

src/metabase/models/interface.clj

src/metabase/models/metric.clj

src/metabase/models/pulse.clj

src/metabase/models/revision.clj

src/metabase/models/segment.clj

test/metabase/api/metric_test.clj

test/metabase/api/pulse_test.clj

test/metabase/api/segment_test.clj

test/metabase/models/metric_test.clj

test/metabase/models/segment_test.clj