Support for order-sign Hook

[c-schuler]

Builds on PR #151

• Added Rx Sign tab
• Added actions to support workflow
• Updated reducers to account for supply duration, intent and category (needed for opioid content)

Partially addresses #93

I could take steps in merging this functionality into the Rx View tab if that is preferable.

There is not a default order-sign service available in the initial CDS Service. To test use the following configuration:
FHIR Server: https://opioid-sandbox.cqframework.org/cdc/opioid-cds-r4/ehr/fhir
Patient ID: example-opioidcds
CDS Service Discovery: https://opioid-sandbox.cqframework.org/cdc/opioid-cds-r4/cds-service/cds-services

[jmandel]

I'm torn between

• At a high level "it feels right" to have a single flow that covers/triggers order view and sign at the appropriate points in the workflow (better simulating what a real clinical system would do). This argues for merging the view and sign UX into a single tab.
• Pragmatically if a developer is working on a specific hook, it's nice to have a top level navigation point focused on that hook. This argues for keeping separate tabs.

... Anyway, bringing these improvements in place without undue delay is probably the right principle.

To test use the following configuration:
FHIR Server

We really should support deep links to bring all this configuration to bear. (I could swear we used to, but may have lost it in the rewrite.)