Memory optimization for ScriptEvaluate

[pairbit]

Please add method overloads.
This will allow using ArrayPool.Rent and reuse buffers

Task<RedisResult> ScriptEvaluateMemoryAsync(string script, ReadOnlyMemory<RedisKey> keys, ReadOnlyMemory<RedisValue> values, 
CommandFlags flags = CommandFlags.None)

Task<Lease<byte>?> ScriptEvaluateMemoryLeaseAsync(string script, ReadOnlyMemory<RedisKey> keys, ReadOnlyMemory<RedisValue> values, 
CommandFlags flags = CommandFlags.None)

[atakavci]

hey @mgravell , @NickCraver , would you like to see a PR for this ?? i can go for it.