feat(dashboard): add owner ID to dashboard model
This adds the explicit OwnerID field to Dashboard and also adds a
migration which populates dashboard owners IDs based on dashboard owner
URMs.
feat(dashboards): isolate service in own package
This change isolates the dashboards service into its own package. It
also updates the API to no longer interface with user resource mappings.
Instead it defines new handlers which rely on the newly populated owner
ID field.
chore(dashboards): port tests from http package into new service transport package
chore(launcher): use dashboard transport package client in launcher tests
chore(kv): remove now defunkt dashboard service implementations
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