Update integrations to allow custom checkpoint locations (#1501) (#1511)

* Update integration type for new format



* Update integration type validator for new type



* Fix type errors in integration_reader



* Fix return types in adaptor



* Update integrations constants



* Fix local repository and local repository tests



* Fix remaining integrations unit tests



* Add integration format migration



* Fix frontend usage of integration assets



* Update integration install query iteration



* Add checkpoint field to setup form



* Update checkpoint text based on UI feedback



* Add new checkpoint usage to setup flow



* Split out integrations setup methods



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(cherry picked from commit dec4ff2)

Signed-off-by: Simeon Widdis <sawiddis@amazon.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>