[feat] Cache size option

[robertsLando]

Should this be an option?

aedes-persistence-redis/persistence.js

Line 37 in bd60484

this.messageIdCache = HLRU(100000)

[gnought]

What’s the impact if we set to HLRU to 1?

[robertsLando]

It will allow to have just 1 inflight message (Qos1/2), outgoingUpdate/outgoingClearMessageId will throw error when doesn’t find the key on the cache