feat: default session id

[kwasniew]

About the changes

What problem are we solving?

• enabled info and variant info in the same feature have to be consistent when stickiness is set to default
• also we want to have consistency between parent and child features

Solution:

• if the user didn't provide sessionId, generate one one the fly

Important files

Discussion points

Is Math.random() good enough?

[Tymek]

Is Math.random() good enough?

I think so. In the end we only need it to decide rollout here. Should be good enough for 0.1% splits after our hashing

[sighphyre]

Is Math.random() good enough?

I think so. In the end we only need it to decide rollout here. Should be good enough for 0.1% splits after our hashing

Yeah agreed, I don't think it matters that much in this context