Add missing unit tests for the Random Module hooks

[mosmartin]

Description

Based on the defined test cases, the following tests are missing from the implemented unit tests.

• For the element in the block assets property for the random module, if its seedReveal property is 20 bytes
  • Expectation: validation passes
• For the element in the block assets property for the random module, if its seedReveal property is not 20 bytes
  • Expectation: block processing fails
• check seedReveal property of block assets with isSeedValidInput internal function and update validatorReveals array accordingly
  • Expectation: validatorReveals array of the random state store is updated
  • Update the DEFAULT_MAX_LENGTH_REVEALS to MAX_LENGTH_VALIDATOR_REVEALS as defined in the LIP

Motivation

These test will align with defined test cases and ensure complete coverage of the scenarios.

[mosmartin]

The first two tests are off. The test scenarios provided are incorrect.

The last issue is more cosmetic and does not impact the protocol but would be nice to align.