Add possibility to allowlist scriptlets

[superlex]

uBlock Origin supports example.org#@#+js() to defuse all scriptlets in example.org.

AdGuard should support example.org#@%#//scriptlet() or example.org#@%#//scriptlet('') to do the same thing and convert the first one into that.

Furthermore, AdGuard could also add the ability to defuse a specific scriptlet. For example, if you have

example.org#%#//scriptlet('set-local-storage-item', 'aditem1', '1')
example.org#%#//scriptlet('set-cookie', 'adcook1', '1')
example.org#%#//scriptlet('set-cookie', 'adcook2', '2')

then example.org#@%#//scriptlet('set-cookie') should defuse only the last two, while example.org#@%#//scriptlet() or example.org#@%#//scriptlet('') should defuse all of them.

NB: uBlock Origin also supports #@#+js() (without domain) to suppress all scriptlet in all sites. AdGuard could do the same, if you find it useful. For example, #@%#//scriptlet('set-cookie') (without domain) could defuse all set-cookie scriptlets everywhere.

References: https://github.com/gorhill/uBlock/wiki/Static-filter-syntax#scriptlet-injection