Allow "AND", "OR", "IN" groupings in filters

Long time customer of Postico. Every month or two I'm in some situation where I'd really like to setup a bunch of filters with AND/OR groupings (OR groupings often as a workaround for not having "IN") - I end up searching Postico docs hoping there's some way to do it I didn't notice, but no luck.

no filtering ability to do some simple things like
`SELECT * WHERE ("a" = '123' OR "a" = '234')`
or
`SELECT * WHERE "b" = TRUE AND ("a" = TRUE OR "c" = TRUE)`

I do get that there are variously complex UI and code ways you could implement these groups, but even the simplest start would be nice in the developer branch

Thanks
-j

Start by reviewing Postico's existing filter behavior and the documentation referenced in the issue, then trace how filter expressions are assembled. Compare the requested AND/OR examples, including IN-like behavior, with the current developer branch. Done means grouped filter expressions work for these cases and their behavior is documented.

Written by the indexing model from the issue text.