@angular/common/http has XSRF protection which is enabled by default and is
implemented as an interceptor. Previously, this protection could be disabled
with an API which would internally provide a `NoopInterceptor` in place of
the standard XSRF interceptor.
To achieve the same capability of disabling the XSRF interceptor after it is
converted to the functional style, an InjectionToken is added in this commit
which disables the XSRF interceptor. This way, the interceptor can be
disabled in place without needing to override it via DI (which is difficult
for functional interceptors).
PR Close#47502
In combination with the TS `noImplicitOverride` compatibility changes,
we also want to follow the best-practice of adding `override` to
members which are implemented as part of abstract classes. This
commit fixes all instances which will be flagged as part of the
custom `no-implicit-override-abstract` TSLint rule.
PR Close#42512
Alex Rickabaugh