Add ability to filter libraries, collection, etc (#308)

Adds a button to filter contents next to the sort button on grid pages

The filters are saved and restored you return to the page. It works with
#278, playing the filtered items in the sorted order.

The drop down menus for both sorting & filtering are updated to closer
match the overall look.

Filters for:
- Played or unplayed
- Favorite or not
- Genres
- Community (star) rating
- Parental rating
- Video type (HD vs SD, etc)
- Release year and/or decade

app/src/main/res/values/fa_strings.xml

@@ -38,4 +38,5 @@
     <string name="fa_volume_low" translatable="false">&#xf027;</string>
     <string name="fa_ellipsis" translatable="false">&#xf141;</string>
     <string name="fa_ellipsis_vertical" translatable="false">&#xf142;</string>
+    <string name="fa_filter" translatable="false">&#xf0b0;</string>
 </resources>