Fix wrapCommand for async command execution

[christian-bromann]

Proposed changes

The PR #4853 caused a regression with async test execution. This patch fixes it and adds smoke tests for async test runner execution.

closes #4849

Types of changes

• 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

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 necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

Reviewers: @webdriverio/technical-committee

[mgrybyk]

LGTM, let's wait for tests to pass

[codecov]

Codecov Report

Merging #4858 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4858      +/-   ##
==========================================
+ Coverage   99.39%   99.39%   +<.01%     
==========================================
  Files         209      209              
  Lines        5470     5480      +10     
  Branches     1194     1196       +2     
==========================================
+ Hits         5437     5447      +10     
  Misses         30       30              
  Partials        3        3

Impacted Files	Coverage Δ
packages/wdio-utils/src/shim.js	100% <100%> (ø)	⬆️

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[mgrybyk]

👍