[Library] Feed library (#4)

This PR contains the work done to setup the library and also, the necessary protocols, model, structs, and error definitions to implement remote service clients.

Reviewed-on: rock-n-code/app-reviews#4
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Test Plans/Libraries.xctestplan

@@ -0,0 +1,24 @@
+{
+  "configurations" : [
+    {
+      "id" : "BF43DE96-4FFB-475F-B056-3EE94ACD1F54",
+      "name" : "Test Scheme Action",
+      "options" : {
+
+      }
+    }
+  ],
+  "defaultOptions" : {
+    "codeCoverage" : false
+  },
+  "testTargets" : [
+    {
+      "target" : {
+        "containerPath" : "container:Libraries",
+        "identifier" : "ReviewsFoundationTest",
+        "name" : "ReviewsFoundationTest"
+      }
+    }
+  ],
+  "version" : 1
+}