Add subscription validation APIs and runtime functions. (#847)

CHANGELOG.md

apigrpc/apigrpc.pb.go

apigrpc/apigrpc.pb.gw.go

apigrpc/apigrpc.proto

apigrpc/apigrpc.swagger.json

apigrpc/apigrpc_grpc.pb.go

console/console.pb.go

console/console.pb.gw.go

console/console.proto

console/console.swagger.json

console/console_grpc.pb.go

console/ui/dist/index.html

console/ui/dist/static/main.0b74ccf8d7e0caf7719b.js

console/ui/src/app/account/account.component.ts

console/ui/src/app/account/purchases/purchases.component.ts

...rc/app/account/subscriptions/subscriptions.component.html

...rc/app/account/subscriptions/subscriptions.component.scss

.../src/app/account/subscriptions/subscriptions.component.ts

console/ui/src/app/app-routing.module.ts

console/ui/src/app/app.module.ts