Read fund-store host from parameter store

This will help us migrate from the "microservice"-y fund-store to a more
consolidated pre-award-stores service.

Ticket: https://mhclgdigital.atlassian.net/browse/FSPT-108

copilot/fsd-assessment-store/manifest.yml

@@ -47,7 +47,6 @@ variables:
   FLASK_ENV: ${COPILOT_ENVIRONMENT_NAME}
   APPLICATION_STORE_API_HOST: http://fsd-application-store:8080
   ACCOUNT_STORE_API_HOST: http://fsd-account-store:8080
-  FUND_STORE_API_HOST: http://fsd-fund-store:8080
   ASSESSMENT_FRONTEND_HOST: "https://assessment.${COPILOT_ENVIRONMENT_NAME}.access-funding.test.levellingup.gov.uk"
   AWS_MSG_BUCKET_NAME:
     from_cfn: ${COPILOT_APPLICATION_NAME}-${COPILOT_ENVIRONMENT_NAME}-MessageBucket
@@ -61,6 +60,7 @@ variables:
     from_cfn: ${COPILOT_APPLICATION_NAME}-${COPILOT_ENVIRONMENT_NAME}-NotificationDeadLetterQueueURL
 
 secrets:
+  FUND_STORE_API_HOST: /copilot/${COPILOT_APPLICATION_NAME}/${COPILOT_ENVIRONMENT_NAME}/secrets/FUND_STORE_API_HOST
   SECRET_KEY: /copilot/${COPILOT_APPLICATION_NAME}/${COPILOT_ENVIRONMENT_NAME}/secrets/SECRET_KEY
 
 # You can override any of the values defined above by environment.