Changed NewBlockDialog validator

[drpayyne]

Description

This PR changes the validator used by NewBlockDialog.

Fixed Issues

1. Change validation for the new block dialog window #295: Change validation for the new block dialog window

Additional Changes

• Added new validation rule called PHP_DIRECTORY which used the class PhpDirectoryRule. This ensures that the value is just like a PHP class name ([A-Z][a-zA-Z0-9]+) but uses an appropriate error message: The {0} field does not contain a valid PHP directory
• Also contains changes from 26504ab to modify the logic of PHP class validation
• Fixed grammar in error message

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with integration/functional tests (if applicable)
• All automated tests passed successfully (all builds are green)

[coderimus]

Hi @drpayyne ,
Thank you for the provided changes. Looks good 👍