Add issues for 8.x Milestone 3

#2245015: [META] Rules 8.x Roadmap currently has no sub-issues for Milestone 3.

For each task under Milestone 3, we should add an issue and link them here, once linked, we can update the parent issue.

issue template:

Title: Task title

Project: Rules
Version: 8.x-3.x-dev
Component: Rules Core
Priority: Normal
Category: Task
Assigned: Unassigned

Parent issue: [META] Rules 8.x Roadmap (2245015)

it is not necessary to apply the d8rules tag to those issue, we will only be using it for drupal 8 core issues related to Rules 8.x and main issues like the roadmap.