Add validation for allowlist

### AdGuard Extension version

4.2.226

### Browser version

119.0.6045.160 (Official) (64-bit)

### OS version

Windows 10

### What filters do you have enabled?

AdGuard Base filter, AdGuard Annoyances filter, AdGuard Cookie Notices filter, AdGuard Popups filter, EasyList China, EasyList Germany, EasyList Italy, Liste FR, Official Polish filters for AdBlock, uBlock Origin & AdGuard, Polish Social Filters, EasyList Spanish, KAD - Anti-Scam, Polish Annoyances Filters, Polish Anti Adblock Filters, NoCoin Filter List, EasyList Polish, Polish Anti-Annoying Special Supplement

### What Stealth Mode options do you have enabled?

_No response_

### Issue Details

Extension keeps turning off - the icon is greyed out, so I am trying to turn on the protection, seems like it works, but after reloading the page - again it is turne off and no protection is applied.

### Expected Behavior

AdGuard protection working as usual.

### Screenshots

Screenshot 1: after starting the chrome browser and entering *any* page


Screenshot 2: when I tap on the switch, page reloads and switch shows green [but the icon is still greyed]


Screenshot 3: so I close the AdGuard's popup, again press on the icon and see the switch turned off:


### Additional Information

_No response_