chore: Refactor Checks workflow

[kpavlov]

Improve matrix jobs for tests

• Run single gradle command instead of multiple; Tune gradle tasks per platform.
• Run jsTest and relocate failing ConfigurationLoadingTest to jvmTest directory.
• Don't run jvm tests on macOS; run only iOS simulator jobs

Motivation and Context

Make building faster and GH workflow cleaner

Breaking Changes

No

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Type of the changes

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Tests improvement
• Refactoring
• CI/CD changes
• Dependencies update

Checklist

• The pull request has a description of the proposed change
• I read the Contributing Guidelines before opening the pull request
• The pull request uses develop as the base branch
• Tests for the changes have been added
• All new and existing tests passed

Additional steps for pull requests adding a new feature

• An issue describing the proposed change exists
• The pull request includes a link to the issue
• The change was discussed and approved in the issue
• Docs have been added / updated

[aozherelyeva]

LGTM, thanks, but I'd wait for someone from the team to approve as well (just in case)