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/gitlab_test.go

@@ -43,7 +43,7 @@ func TestGitLabDriver(t *testing.T) {
 	r := records[0]
 	assert.NotEmpty(t, r.ExternalID)
 	assert.NotEmpty(t, r.FullName)
-	assert.NotEmpty(t, r.Role)
+	assert.NotEmpty(t, r.Roles)
 	assert.Equal(t, coredata.MFAStatusUnknown, r.MFAStatus)
 	require.NotNil(t, r.Active)
 	assert.True(t, *r.Active)