Add proxying gravatar requests for user avatars (#148)

Fix getting avatar based on email

Remove avatarUrl from user struct

Fix staticcheck

Add default avatar size

Add config option for caching avatars

go mod vendor

Add swagger docs

Add proxying gravatar requests for user avatars

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/148

pkg/models/task_collection_test.go

@@ -29,24 +29,21 @@ import (
 func TestTaskCollection_ReadAll(t *testing.T) {
 	// Dummy users
 	user1 := &user.User{
-		ID:        1,
-		Username:  "user1",
-		Password:  "$2a$14$dcadBoMBL9jQoOcZK8Fju.cy0Ptx2oZECkKLnaa8ekRoTFe1w7To.",
-		IsActive:  true,
-		AvatarURL: "111d68d06e2d317b5a59c2c6c5bad808", // hash for ""
+		ID:       1,
+		Username: "user1",
+		Password: "$2a$14$dcadBoMBL9jQoOcZK8Fju.cy0Ptx2oZECkKLnaa8ekRoTFe1w7To.",
+		IsActive: true,
 	}
 	user2 := &user.User{
-		ID:        2,
-		Username:  "user2",
-		Password:  "$2a$14$dcadBoMBL9jQoOcZK8Fju.cy0Ptx2oZECkKLnaa8ekRoTFe1w7To.",
-		AvatarURL: "ab53a2911ddf9b4817ac01ddcd3d975f", // hash for ""
+		ID:       2,
+		Username: "user2",
+		Password: "$2a$14$dcadBoMBL9jQoOcZK8Fju.cy0Ptx2oZECkKLnaa8ekRoTFe1w7To.",
 	}
 	user6 := &user.User{
-		ID:        6,
-		Username:  "user6",
-		Password:  "$2a$14$dcadBoMBL9jQoOcZK8Fju.cy0Ptx2oZECkKLnaa8ekRoTFe1w7To.",
-		IsActive:  true,
-		AvatarURL: "3efbe51f864c6666bc27caf4c6ff90ed", // hash for ""
+		ID:       6,
+		Username: "user6",
+		Password: "$2a$14$dcadBoMBL9jQoOcZK8Fju.cy0Ptx2oZECkKLnaa8ekRoTFe1w7To.",
+		IsActive: true,
 	}
 
 	// We use individual variables for the tasks here to be able to rearrange or remove ones more easily