Refactor: remove unnecessary indirectness in get default form state test (rjsf-team#4462)

* refactor `getDefaultFormState` tests

* refactor `computeDefaults` tests

* refactor `getDefaultBasedOnSchemaType` tests

* refactor `getObjectDefaults` tests

* refactor `getArrayDefaults` tests

* replace original `getDefaultFormStateTest` test with refactored

* clarify expected value for array test

* remove unused type

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Co-authored-by: Heath C <[email protected]>

Author: x0k