bumped to php 8.1

added ajax validation reload if wrong

added possibility to override clientOptions

fixed random hex generation

bumped to php 7.3

prevent direct access to captcha script

prevent access to captcha script if referrer does not match to host

removed client validator (don't works well)

updated visual captcha asset (followed base logic)

added client validator to `VisualCaptchaValidator`

updated base version constraint

updated base version constraint