(fix) BaseTrackCache: fix filterAndSort() to avoid unwanted extra tracks with extraFilter

[ronso0]

Fixes #14873 and similar symptoms in #14687 for me.
I only understand parts of BaseTrackCache, so I don't know how this can affect the 'dirty tracks' thing in real life.

The issue:

In #14687 tracks pop up in the Computer directory views that use LibraryTableModel.
Same for #14873, unrelated (older) tracks show up in Analyze view.

Root cause:

So called "extra filters" are sent to SearchQueryParser::parseQuery(query, extraFilter) where extraFilter is wrapped as SqlNode.
In BaseTrackCache we add dirty tracks to the current view if they are missing but match the query -- however the extraFilter SqlNode::match(pTrack) always returns true, making the check pointless because it adds dirty tracks even if they don't belong into the view.

Fix:

refine that check and only consider SqlNode::Match() if the extraFilter is empty.

As far as I can tell, Analyze (and #14687) are the only features that make use of the extra filter.
But I'm not sure, so there may be side effects for other library views, too.

[ronso0]

As far as I can tell, Analyze (and #14687) are the only features that make use of the extra filter.

If this is true, and we use extraFilter only for _basic_¹ filtering, we could as well

1. fix the datetime_added filter (this is currently a TextFilterNode 🙄 )
2. make extraFilter an OrNode -> parses text input like from searchbar
3. rework the date added filter in Analyze (date > now - 7 days)
4. (add a directory filter for use in (feat) Computer feature: use library data model if selected path is watched by library #14687)

¹ basic like use search operators like users do via searchbar