* pulseeffects: change default example
pulseeffects-pw is now an alias to easyeffects, and the `pulseeffects` binary
that this module references is no longer in that package.
* easyeffects: add module
The easyeffects service is the PipeWire equivalent of the pulseeffects
service.
Before, loading a module would be guarded by an optional platform
condition. This made it possible to avoid loading and evaluating a
module if it did not support the host platform.
Unfortunately, this made it impossible to share a single configuration
between GNU/Linux and Darwin hosts, which some wish to do.
This removes the conditional load and instead inserts host platform
assertions in the modules that are platform specific.
Fixes#1906
