Fast switching should behave better with async commands

This reverts commit 63506d5a.

For cross renderers spu text sizing

Will never end, because the only tags permitting
differentiation from raw M3U only comes last in the playlist.

Now queues stream_Demux callbacks and data as commands
and handle es recycling when possible.

Avoids dropping data on ES/quality change.

The input thread and input manager have no use for this.

Also fix leaks of the above and on-error NULL dereference.

Reset is at initialization, or after seekpoint seek.

Fixes #15140

If downstream is paused while the buffer is not full, continue
fetching. When the buffer is full, pause.

This function returns of list of hacks that are needed for codec
initialization, and also include IgnoreOmxDecoderPadding hack.

Remove OMX.MTK.VIDEO.DECODER.MPEG4 from blacklist since it only need a valid
CSD.

Rename it to pf_process_output. The output buffer is now dequeued/parsed
outside of the pf callback.

This commit also removes the decoder_NewPicture HACK to know if decoder is
flushing.