Add ability to inject scriptlets according to origin of ancestor contexts (uBO)

[piquark6046]

https://github.com/gorhill/uBlock/commit/a483f7955fc8c9c820684c3f55c9f982a7abb2d3

I think that in an AdGuard filter, we can write it like

example.com>>#%#//scriptlet('set-constant', 'iAmEmbeddedInExampleDotCom', 'true')

[AdamWr]

I guess related to https://github.com/AdguardTeam/CoreLibs/issues/1969