[plaster] `PermissionContextBase` migration
The introduction of plasters for `PermissionContextBase` gets rid of a
lot of replacement cruft that was really difficult to make sense of.
This change also tweaks the interface for
`BraveCanBypassEmbeddingOriginCheck`, so it can make the plaster simpler
for this substitution too.
The core of this change is to move `PermissionContextBase` in upstream
into `chromium_impl::`, and derive our own implementatiom from that,
which simplifies a lot of the issues with naming replacement everywhere.
Resolves https://github.com/brave/brave-browser/issues/54952
cdesouza-chromium
3bb82b9e52