feat($route): add support for the `reloadOnUrl` configuration option

Enables users to specify that a particular route should not be reloaded after a
URL change (including a change in `$location.path()`), if the new URL maps to
the same route.
The default behavior is still to always load the matched route when any part of
the URL changes.

Related to #1699, #5860, #14999 (potentially closing the first two).

Fixes #7925

Closes #15002