[FEATURE] Improve telemetry error handling

[Kavindu-Dodan]

Requirements

Consider this conversation - https://github.com/open-feature/flagd/pull/1188#discussion_r1475580979

In the current implementation, errors in telemetry at the startup phase result in startup failure. While this has benefits, telemetry can be considered as non-critical sub-system and allow flagd/flagd-proxy to startup with warnings.

AC

Revisit configuration and startup logic. Migrate from fail fast to log and continue for telemetry errors.