Local payments performance script

[mkurapov]

Context

Currently, we have a performance test script that goes through the steps of making a payment (create incoming payment, create quote, create outgoing payment) between two different Rafikis. With the introduction of local payments in #2834, we also want to be able to measure the performance of "local" payments that happen within the same Rafiki instance.

For this issue, let's create a script that is very similar to the existing rafiki/test/performance/scripts/create-outgoing-payments.js script, except instead of doing the steps across two Rafikis, we will have all the resources (incoming payment, quote, and outgoing payment) be created on the same, cloud-nine-wallet, Rafiki instance.

Todo

• Create k6 script in rafiki/test/performance/scripts/ that sets up a local payment in the same Rafiki