Parse & scrub lowercase redis commands

[jjbayer]

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

relay/relay-event-normalization/src/normalize/span/description/mod.rs

Lines 1142 to 1143 in c6d9110

	// NOTE: this should return `DEL *`, but we cannot detect lowercase command names yet.
	assert_eq!(scrubbed.0.as_deref(), Some("*"));

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