nimiq-primitives: Node crash due to missing interlink validation in election macro block proposals

nimiq-primitives contains primitives (e.g., block, account, transaction) to be used in Nimiq's Rust implementation. Prior to version 1.3.0, an untrusted p2p peer can cause a node to panic by announcing an election macro block whose `validators` set contains an invalid compressed BLS voting key. Hashing an election macro header hashes `validators` and reaches `Validators::voting_keys()`, which calls `validator.voting_key.uncompress().unwrap()` and panics on invalid bytes. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.