fix(designer): fix actions and triggers title not showing in dark theme

[tbabatund]

• Please check if the PR fulfills these requirements

• [x] The commit message follows our guidelines

• [x] Tests for the changes have been added (for bug fixes/features)

• [x] Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...) Bug

• What is the current behavior? (You can also link to an open issue here) When designer is set to dark mode, triggers and actions title does not show https://msazure.visualstudio.com/One/_workitems/edit/27320697

• What is the new behavior (if this is a feature change)? Triggers and actions titles now shows when app is in dark mode

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?) No

• Please Include Screenshots or Videos of the intended change:

  

[tbabatund]

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