Add EPG filter for categories
If xmltv is providing categories then it is useful to be able to filter at the EPG similar to existing genre filter.
dvr: Fix autorec if it has a category but event has no category. (#4777).
Although we use a drop-down list for autorec categories, if the
user has no categories enabled (such as OTA) and creates an autorec
with a category then it would match all events.
Now we fix it that events without a category can never match an
autorec with categories.
ui: Allow filtering/autorec from EPG by category. (#4777).
If we have categories on the server (from xmltv) then
we create a second toolbar on the EPG and add filters for
filtering by category. These are then included in the
autorec rule created from the EPG.
We use a second toolbar since the primary toolbar is a
too cramped to fit more search drop-down boxes.