Store a security origin for a third-party check in BraveRequestInfo

[atuchin-m]

Instead of working with (origin) request initiator we need to calculate and store the proper security origin for 1p/3p check in BraveRequestInfo.
Maybe it make sense to use: https://source.chromium.org/chromium/chromium/src/+/main:components/subresource_filter/core/common/first_party_origin.h;l=21?q=first_party_origin.h (or reimplement it).

brave/brave-core#38539 (comment)