Add internal escaping for special characters in regular expressions for better compatibility with uBO

[Alex-302]

https://github.com/AdguardTeam/FiltersRegistry/pull/802/files#diff-eafb4aff19bc57c3106afe5e1d4aef0b6422e0de242745e6e94f7d5733ab1cc1R4504 The rules from the filters, which use uBO syntax:

Error: "Unknown modifier: all" in the rule: "/(\.|//|^)1xslot\d{5,}\.com(/|$)/$all,~inline-font,~inline-script"
Error: "Unknown modifier: all" in the rule: "/(\.|//|^)1xslot\d{5,}\.com(/|$)/$all"