Invalid cql-json `and` expression is parsed into "wrong" ast

I cannot find any description of how pygeofilter is supposed to behave when it meets invalid filters. The issue is written assuming that pygeofilter should fail when parsing invalid filters.

Example 1 where pygeofilter silently ignores invalid `and` expression:
```
>>> import pygeofilter.ast
>>> from pygeofilter.parsers.cql_json import parse as parse_json
>>>
>>> cql_json = { "intersects": [ { "property": "geometry" }, { "type": "Point", "coordinates": [ 10.4064, 55.3951 ] } ], "and": [ {"eq": [ { "property": "direction" }, "east" ] } ] }
>>> print(pygeofilter.ast.get_repr(parse_json(cql_json)))
INTERSECTS(ATTRIBUTE geometry, Geometry(geometry={'type': 'Point', 'coordinates': [10.4064, 55.3951]}))
```

Example 2 where pygeofilter parses invalid `and` into a simple comparison:
```
>>> import pygeofilter.ast
>>> from pygeofilter.parsers.cql_json import parse as parse_json
>>>
>>> cql_json = { "and": [ {"eq": [ { "property": "direction" }, "east" ] } ] }
>>> print(pygeofilter.ast.get_repr(parse_json(cql_json)))
ATTRIBUTE direction = 'east'
```

Needless to say it would be a better user experience if both these examples would fail with some meaningful message.