This commit moves the parsing, compiling and enforcement
of the `redirect=` and `redirect-rule=` network filter
options into the static network filtering engine as
modifier options -- just like `csp=` and `queryprune=`.
This solves the two following issues:
- https://github.com/gorhill/uBlock/issues/3590
- https://github.com/uBlockOrigin/uBlock-issues/issues/1008#issuecomment-716164214
Additionally, `redirect=` option is not longer afflicted
by static network filtering syntax quirks, `redirect=`
filters can be used with any other static filtering
modifier options, can be excepted using `@@` and can be
badfilter-ed.
Since more than one `redirect=` directives could be found
to apply to a single network request, the concept of
redirect priority is introduced.
By default, `redirect=` directives have an implicit
priority of 0. Filter authors can declare an explicit
priority by appending `:[integer]` to the token of the
`redirect=` option, for example:
||example.com/*.js$1p,script,redirect=noopjs:100
The priority dictates which redirect token out of many
will be ultimately used. Cases of multiple `redirect=`
directives applying to a single blocked network request
are expected to be rather unlikely.
Explicit redirect priority should be used if and only if
there is a case of redirect ambiguity to solve.