Add indexes to process_request_tokens

[nolanpro]

Issue & Reproduction Steps

Task PMQL searches and charts are slow.

Solution

This adds 3 indexes recommended by Tighten

• status
• element_type
• composite status and is_self_service

How to Test

• Performance will only be noticeable where there are lots of process requests and tasks
• Compare the XHR response time for http://processmaker-a.test/api/1.0/tasks when searching with PMQL status = "active" AND is_self_service = 1 on the tasks page

Related Tickets & Packages

• https://processmaker.atlassian.net/browse/FOUR-8347

Code Review Checklist

• I have pulled this code locally and tested it on my instance, along with any associated packages.
• This code adheres to ProcessMaker Coding Guidelines.
• This code includes a unit test or an E2E test that tests its functionality, or is covered by an existing test.
• This solution fixes the bug reported in the original ticket.
• This solution does not alter the expected output of a component in a way that would break existing Processes.
• This solution does not implement any breaking changes that would invalidate documentation or cause existing Processes to fail.
• This solution has been tested with enterprise packages that rely on its functionality and does not introduce bugs in those packages.
• This code does not duplicate functionality that already exists in the framework or in ProcessMaker.
• This ticket conforms to the PRD associated with this part of ProcessMaker.