Add option to write custom SQL filters for experienced users.

[RaczeQ]

Prepare a grammar language for writing custom SQL filters (simplest option for users - utilize replacement, simplest option to implement - allow users to use DuckDB functions and expect them to use it)

Examples:

-- Queries provided by user

-- Option 1: probably simplest for the end user, will require additional step to unnest all key value pairs
(osm_tag_key = 'highway' AND (osm_tag_value LIKE '%ary' OR osm_tag_value = 'motorway'))

-- Expanded in the QuackOSM query
WITH raw_data AS (
    SELECT kind, id, tags
    FROM ST_ReadOSM('tests/test_files/monaco.osm.pbf')
    WHERE tags IS NOT NULL
), 
unnested_data AS (
    SELECT kind, id, UNNEST(map_entries(tags)) kv_pair
    FROM raw_data
), 
expanded_data AS (
    SELECT kind, id, kv_pair['key'] as osm_tag_key, kv_pair['value'] as osm_tag_value
    FROM unnested_data
),
filtered_elements AS (
    SELECT DISTINCT kind, id
    FROM expanded_data
    -- paste filter here 1 to 1
    WHERE (osm_tag_key = 'highway' AND (osm_tag_value LIKE '%ary' OR osm_tag_value = 'motorway'))
)
SELECT *
FROM raw_data
SEMI JOIN filtered_elements USING (kind, id)