Parse & scrub lowercase redis commands

[jjbayer]

Not all redis integrations send uppercase redis commands, which results in redis spans being scrubbed as *. See

https://github.com/getsentry/relay/blob/c6d911004dc743289c5142ac0a54e6df17ac1a42/relay-event-normalization/src/normalize/span/description/mod.rs#L1142-L1143

Solution: Either use a proper redis parser or allowlist some of the most common commands (get, set, evalsha, ...).