[UIK-5242][bulk-textarea] fixed clearAll button with defaultValue only

[ilyabrower]

Changelog

@semcore/bulk-textarea

Fixed

• The value wasn't cleared by the clearAll button when using only defaultValue.

Motivation and Context

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (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).
• Nice improve.

Checklist:

• I have updated the documentation accordingly.
• I have added new tests on added of fixed functionality.