(prototype) Create download verifier IDEs task

[aSemy]

Pull Request Details

This is a prototype to demonstrate how the IDE downloading can be split into a specific task.

It is not ready because it breaks compatibility with the Gradle configuration cache, and includes some minor API changes that could be smoothed over.

Description

• should improve caching and performance
• update some task properties to use Gradle file system types and the correct annotations (helps with connecting task inputs/outputs)
• this breaks configuration cache compatibility, as the downloading now occurs in the 'execute' phase, while previously it occurred in the 'configuration' phase
• I re-used the existing 'download' code as much as possible, but I think it should be refactored to be more simple

Related Issue

• #1142
• #1114
• #1134

Motivation and Context

How Has This Been Tested

Types of changes

• [ ] Docs change / refactoring / dependency upgrade
• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ ] I have read the CONTRIBUTING document.
• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have included my change in the CHANGELOG.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.