feat: soft assert

[kobenguyent]

Motivation/Description of the PR

• Soft assert

Zero-configuration when paired with other helpers like REST, Playwright:

// inside codecept.conf.js
{
  helpers: {
    Playwright: {...},
    SoftExpectHelper: {},
  }
}

// in scenario
I.softExpectEqual('a', 'b')
I.flushSoftAssertions() // Throws an error if any soft assertions have failed. The error message contains all the accumulated failures.

Type of change

• 🚀 New functionality

Checklist:

• Tests have been added
• Documentation has been added (Run npm run docs)
• Lint checking (Run npm run lint)
• Local tests are passed (Run npm test)