[Remote signer] Add signer consumer lib (#1763)

Adds a library `common/remote_signer_consumer`

testing/remote_signer_test/src/remote_signer_test_data.rs

@@ -0,0 +1,69 @@
+use crate::*;
+use remote_signer_consumer::RemoteSignerObject;
+use std::marker::PhantomData;
+use types::{AttestationData, BeaconBlock, Domain, Epoch, EthSpec, Fork, Hash256};
+
+pub struct RemoteSignerTestData<E: EthSpec, T: RemoteSignerObject> {
+    pub public_key: String,
+    pub bls_domain: Domain,
+    pub data: T,
+    pub fork: Fork,
+    pub genesis_validators_root: Hash256,
+
+    _phantom: PhantomData<E>,
+}
+
+impl<'a, E: EthSpec, T: RemoteSignerObject> RemoteSignerTestData<E, T> {
+    pub fn new(public_key: &str, data: T, bls_domain: Domain) -> Self {
+        let epoch = data.get_epoch();
+
+        Self {
+            public_key: public_key.to_string(),
+            bls_domain,
+            data,
+            fork: Fork {
+                previous_version: [1; 4],
+                current_version: [2; 4],
+                epoch,
+            },
+            genesis_validators_root: Hash256::from_low_u64_be(0xc137),
+
+            _phantom: PhantomData,
+        }
+    }
+}
+
+pub fn get_input_data_block(seed: u64) -> RemoteSignerTestData<E, BeaconBlock<E>> {
+    let block = get_block::<E>(seed);
+    RemoteSignerTestData::new(PUBLIC_KEY_1, block, Domain::BeaconProposer)
+}
+
+pub fn get_input_data_attestation(seed: u64) -> RemoteSignerTestData<E, AttestationData> {
+    let attestation = get_attestation::<E>(seed);
+    RemoteSignerTestData::new(PUBLIC_KEY_1, attestation, Domain::BeaconAttester)
+}
+
+pub fn get_input_data_randao(seed: u64) -> RemoteSignerTestData<E, Epoch> {
+    let epoch = Epoch::new(seed);
+    RemoteSignerTestData::new(PUBLIC_KEY_1, epoch, Domain::Randao)
+}
+
+pub fn get_input_data_and_set_domain<E: EthSpec, T: RemoteSignerObject>(
+    f: fn(u64) -> RemoteSignerTestData<E, T>,
+    bls_domain: Domain,
+) -> RemoteSignerTestData<E, T> {
+    let mut test_input = f(0xc137);
+    test_input.bls_domain = bls_domain;
+
+    test_input
+}
+
+pub fn get_input_data_and_set_public_key<E: EthSpec, T: RemoteSignerObject>(
+    f: fn(u64) -> RemoteSignerTestData<E, T>,
+    p: &str,
+) -> RemoteSignerTestData<E, T> {
+    let mut test_input = f(0xc137);
+    test_input.public_key = p.to_string();
+
+    test_input
+}