Tempo-k8s does not capture traces for charm install hook + traces not captured prior to relation formation

[shayancanonical]

Enhancement Proposal

The tempo-k8s integration does not capture traces for the install hook because tracing-relation-created event will always run after the install hook of the charm if the tracing relation is created before the charm is provisioned

Furthermore, if there are events that are run before the tracing relation is created, all those traces are lost.

Suggestion: somehow locally cache the trace information for all events run before the tracing relation is formed. These cached traces can then be pushed to tempo as soon as the tracing relation is formed. There may be concerns about how many traces should be cached on the charm (in case the tracing relation is never formed), but these cached traces can be purged to ensure that only the last N traces are available on a charm at any given time