user service: add oauth and profile images (#17784)

* users: add cache to service

* reflect review comments

* add oauth

* move profile picture genaration

* reflect review comments

* move default bot image to users package

* add missing wraps and apply suggestions

* add comment for app.GetSession

app/user_test.go

@@ -8,8 +8,6 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
-	"image"
-	"image/color"
 	"strings"
 	"testing"
 	"time"
@@ -82,19 +80,6 @@ func TestCreateOAuthUser(t *testing.T) {
 	})
 }
 
-func TestCreateProfileImage(t *testing.T) {
-	b, err := CreateProfileImage("Corey Hulen", "eo1zkdr96pdj98pjmq8zy35wba", "nunito-bold.ttf")
-	require.Nil(t, err)
-
-	rdr := bytes.NewReader(b)
-	img, _, err2 := image.Decode(rdr)
-	require.NoError(t, err2)
-
-	colorful := color.RGBA{116, 49, 196, 255}
-
-	require.Equal(t, colorful, img.At(1, 1), "Failed to create correct color")
-}
-
 func TestSetDefaultProfileImage(t *testing.T) {
 	th := Setup(t).InitBasic()
 	defer th.TearDown()