Truncate access review roles with badge list

Long role strings in the access review table broke row layout when
drivers joined many roles into one comma-separated value. Expose
roles as a string array in GraphQL by splitting the stored role at
the API layer, and render the first three roles as badges with a
"+X more" popover for the rest.

Closes ENG-459.

Signed-off-by: Ludovic Vielle <ludovic@probo.com>

pkg/accessreview/drivers/heroku_test.go

@@ -46,7 +46,7 @@ func TestHerokuDriver(t *testing.T) {
 	assert.NotEmpty(t, r.Email)
 	assert.NotEmpty(t, r.ExternalID)
 	assert.NotEmpty(t, r.FullName)
-	assert.NotEmpty(t, r.Role)
+	assert.NotEmpty(t, r.Roles)
 	assert.Equal(t, coredata.MFAStatusEnabled, r.MFAStatus)
 	assert.True(t, r.IsAdmin)
 	require.NotNil(t, r.CreatedAt)
@@ -106,7 +106,7 @@ func TestHerokuDriverPersonalAccount(t *testing.T) {
 	assert.Contains(t, byEmail, "carol@example.com")
 
 	assert.True(t, byEmail["alice@example.com"].IsAdmin)
-	assert.Equal(t, "owner", byEmail["alice@example.com"].Role)
+	assert.Equal(t, []string{"owner"}, byEmail["alice@example.com"].Roles)
 	assert.False(t, byEmail["bob@example.com"].IsAdmin)
 }