Add support for TLS / HTTPS to `loki.source.api` and `prometheus.receive_http`

### Request

Currently there's no HTTPS / TLS support in [loki.source.api](https://grafana.com/docs/alloy/next/reference/components/loki.source.api/#http) or in [prometheus.receive_http](https://grafana.com/docs/alloy/next/reference/components/prometheus.receive_http/). We should add it and make it configurable. 



### Use case

Securing communications when sending data to Alloy.