[http-spector] Question on `withServiceKeys` usage

Our use case is such:
We have a scenario, which contains multiple endpoints:
- endpoint1
- endpoint2
- endpoint3
- endpoint4

We want a certain set of endpoints to be called in order to consider this scenario pass, e.g. endpoint1 & endpoint3, or endpoint2 & endpoint 4.

How do we express this in Spector?

I tried `withServiceKeys`, e.g.
```typescript
Scenarios.MyScenario = withServiceKeys([
"keyA",
"keyB"
]).pass([
{
uri: endpoint1,
pass: keyA
},
{
uri: endpoint2,
pass: keyA
},
{
uri: endpoint3,
pass: keyB
},
{
uri: endpoint4,
pass: keyB
},
])
```
Though it seems `withServiceKeys` require all endpoints to return both keyA and keyB..

I also tried to set the endpoint as a regex, though it seems we only support string for endpoint uri.

How do we express this?