Add toString() to WolfCryptRandom, init fixes for serialization

[cconlon]

This PR adds a toString() implementation to WolfCryptRandom, which returns the proper string details that are expected from printing a SecureRandom object.

It also makes sure this.rng (Rng) is initialized when methods are called, which fix some edge cases when using serialization of WolfCryptRandom objects.

JUnit tests have been included for regression prevention.

This fixes a few of the OpenJDK SunJCE DRBG tests.

[Copilot]

Pull Request Overview

This PR adds toString() implementation to WolfCryptRandom and fixes serialization edge cases by ensuring the RNG is properly initialized when methods are called. The changes improve compatibility with OpenJDK SunJCE DRBG tests.

• Added toString() method returning standardized DRBG string format
• Implemented lazy initialization pattern to handle serialization/deserialization scenarios
• Added comprehensive JUnit tests for serialization/deserialization functionality

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
WolfCryptRandom.java	Added toString() method, lazy RNG initialization, and null parameter validation
WolfCryptRandomTest.java	Added serialization/deserialization test with helper methods

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