Add postgres database context to chatbot integration

The following SQL query: ```sql SELECT t.table_schema, t.table_name, c.column_name, c.data_type FROM (SELECT table_schema, table_name FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND table_schema NOT IN ('pg_catalog', 'information_schema') ) AS t JOIN information_schema.columns AS c ON t.table_schema = c.table_schema AND t.table_name = c.table_name ORDER BY t.table_schema, t.table_name, c.ordinal_position; ``` Can be used to query information about all tables in a given database. Make an IPC function used by the ElectronAPI that takes in pg connection info and makes the above query. Make the actualy query in. main.ts and wire it up to the app in preload.ts. Make sure to update the types.ts and all the places in the tests where this ElectronAPI type is used.