Issue

at the moment, Tempo exposes one port via ingress - its rest APIs port.
however, each of the ingestion formats Tempo offers is on a different port - that's 8 ports altogether (opentelemetry collector does the same)
ingress library and traefik in their current form are limited to 1 port per ingress
without ingestion exposed via ingress, cross-model tracing works only if both models are within the same k8s cluster.
all charms using charm_tracing use only one protocol - OTLP/HTTP, but we'd eventually like to expose other protocols for workloads as well

Ideas

add a second ingress for OTLP/HTTP to tempo and assume cross-model traces will only be using this protocol for now;
add ingresses for all the ingestion formats and expose each protocol as a separate ingress (which also means a different URL so potentially we might need to change what we store in the databag);
modify traefik charm and add another ingress library for multi-port ingress
use traefik-route