[Searchbox] defaultValue is never used

[cslecours]

Bug Report

• Package version(s): 5.58.0

Priorities and help requested (not applicable if asking question):

Are you willing to submit a PR to fix? If the decided outcome is simple to implement.

Requested priority: (Blocking, High, Normal, Low)

Products/sites affected: (if applicable)

Describe the issue:

The prop defaultValue defined in SearchBox.types.ts is never used in SearchBox.base.tsx.

Actual behavior:

Defining defaultValue does nothing.

Expected behavior:

Either defaultValue should be removed from props, or actually do something.

[jordandrako]

I think I will deprecate it until we are ready to implement uncontrolled text fields.