Use swagger and openapi files to automatically check query field types

[DDorch]

After #14, it is also possible to check the type of the fields (numeric, string) and allow the possibility to use vectors in queries (for example: departement = c(30, 34) and continue to allow the use of string values separated by commas (departement ="30, 34") by parsing the string.

TODO:

• read field type information in swagger/openapi files
• parse array string with comma separator to convert them into string or numeric vectors
• provide error message in case of type mismatch
• convert back array to strings with comma separator for the query URL