refactor: improve performance and coverage of @vscode-wdio/test

[mato533]

Proposed changes

• Improve performance by changing reloading to parallel execution of asynchronous processing.
• Revised UI display during reloading to match other functions
• Improved coverage of @vscode-wdio/test package
• Reduced inter-module dependencies through DI

Types of changes

• Polish (an improvement for an existing feature)
• Bugfix (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 not work as expected)
• Documentation update (improvements to the project's docs)
• Internal updates (everything related to internal scripts, governance documentation and CI files)

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

Reviewers: @webdriverio/project-committers