Add check version functionality (#296)

* Add check version functionality
 * add backend support
 * add ui support
 * minor fixes
 * cosmetic fixes
 * workaround query refetch not working after network error
 * revert changes to Makefile after testing is complete
 * switch to Releases Github API endpoint, add latest Release URL to UI
 * latest version is only shown in UI when version is available and data is ready
 * resolve conflict , squash rebase

graphql/documents/queries/misc.graphql

@@ -66,3 +66,10 @@ query Version {
     build_time
   }
 }
+
+query LatestVersion {
+  latestversion {
+    shorthash
+    url
+  }
+}

graphql/schema/schema.graphql

@@ -96,6 +96,9 @@ type Query {
 
   # Version
   version: Version!
+  
+  # LatestVersion
+  latestversion: ShortVersion!
 }
 
 type Mutation {
@@ -136,4 +139,4 @@ schema {
   query: Query
   mutation: Mutation
   subscription: Subscription
-}
+}

graphql/schema/types/version.graphql

@@ -2,4 +2,9 @@ type Version {
   version: String
   hash: String!
   build_time: String!
-}
+}
+
+type ShortVersion {
+  shorthash: String!
+  url: String!
+}