nostr: filter out `GenericTagValue` variants that do not adhere to the spec #1147

Job	Run time
Build FFI (stable, -p nostr-ffi)	27s
Build no_std (nightly)	1m 14s
Build (stable, -p nostr-sdk --features rocksdb)	17m 21s
Build FFI (stable, -p nostr-sdk-ffi)	1m 43s
Build (stable, -p nostr)	1m 12s
Build (1.66.0, -p nostr-sdk --features rocksdb)	1m 56s
Build (stable, -p nostr --no-default-features --features alloc)	34s
Build WASM (stable, -p nostr)	21s
Build (stable, -p nostr --no-default-features --features "alloc all-nips")	55s
Format	8s
Build WASM (stable, -p nostr-sdk)	58s
Build (stable, -p nostr --features blocking)	1m 19s
Build WASM (stable, -p nostr-sdk --features indexeddb)	52s
Build (stable, -p nostr-database -p nostr-sdk)	1m 45s
Build WASM (stable, -p nostr-js)	17s
Build (stable, -p nostr-sdk --no-default-features)	1m 13s
Build WASM (1.64.0, -p nostr)	4m 55s
Build (stable, -p nostr-sdk --features blocking)	1m 41s
Build WASM (1.64.0, -p nostr-sdk)	5m 15s
Build (stable, -p nostr-sdk --features sqlite)	2m 12s
Build WASM (1.64.0, -p nostr-sdk --features indexeddb)	5m 13s
Build (1.64.0, -p nostr)	5m 33s
Build WASM (1.64.0, -p nostr-js)	5m 53s
Build (1.64.0, -p nostr --no-default-features --features alloc)	4m 58s
Build (1.64.0, -p nostr --no-default-features --features "alloc all-nips")	5m 30s
Build (1.64.0, -p nostr --features blocking)	5m 41s
Build (1.64.0, -p nostr-database -p nostr-sdk)	6m 25s
Build (1.64.0, -p nostr-sdk --no-default-features)	5m 32s
Build (1.64.0, -p nostr-sdk --features blocking)	6m 4s
Build (1.64.0, -p nostr-sdk --features sqlite)	6m 34s
	1h 43m 41s

Provide feedback