Add new validator for custom field checkboxes and fix asset model default updates

[spencerrlongg]

Description

This adds a new validator for checkboxes, as well as adding support for submitting an array for checkbox options through the API.

This also removes the option to encrypt new checkbox custom fields after a conversation with the team.

Tests are included, but not working yet. After a conversation with @marcusmoore there's an issue with the AssetModel factory (if I'm remembering correctly) preventing custom fields from being properly testable, I left the tests in the PR but commented to serve as a reminder to get that fixed and leave them there for future un-commenting.

****Removed the commented tests because they were making all tests fail for some reason, I have them locally so we can re-implement when the factory issue is resolved.

Fixes #SC-24343

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Test Configuration:

• PHP version: 8.1
• MySQL version 8.2

[shortcut-integration]

This pull request has been linked to Shortcut Story #24343: Validation error when using checkboxes on default custom fields models.

[what-the-diff]

PR Summary

• Enhanced Checkbox Handling in Assets Management
  Adjusted the AssetsController file to manage checkboxes better by encoding and decoding their values and changing arrays into strings for simpler handling.

• Updated Model Import Statement
  Modified the import statement for the CustomField model in the AssetModelsController file.

• Validation Enhancements in Custom Fieldset
  Augmented the CustomFieldset file to ensure checkbox values are part of the provided options by performing additional validation.

• Improved Checkbox Validation in Service Provider
  The ValidationServiceProvider file now includes code for better validation of checkboxes, ensuring the submitted values match the provided options.

• Added New Error Message for Checkbox Validation
  Introduced a new error message for the “checkboxes” validation rule in the validation language file.

[spencerrlongg]

@snipe friendly poke

[spencerrlongg]

per @snipe adding some validation for radio buttons as well, please hold

[spencerrlongg]

alright, added @snipe