Deprecation warning when setting `@typeAheadOptionMatcher`

[jhitchins88]

When adding the @typeAheadOptionMatcher as an option to the PowerSelect component, the following deprecation warning:

The <component:power-select::ember585>#typeAheadOptionMatcher computed property was just overriden. This removes the computed property and replaces it with a plain value, and has been deprecated. If you want this behavior, consider defining a setter which does it manually. [deprecation id: computed-property.override] See https://emberjs.com/deprecations/v3.x#toc_computed-property-override for more details.