Query params don't work for MS SQL (pymssql)

[amochin]

This works fine with a lot of DB drivers like oracledb or psycopg2, but fails with pymssql:

*** Variables ***
@{PARAM}    Franz Allan
${QUERY}    SELECT id FROM person WHERE FIRST_NAME=%s

*** Test Cases ***
Test 1
    Query    ${QUERY}    parameters=${PARAM}

Pymssql throws an exception:

ValueError: 'params' arg (<class 'list'>) can be only a tuple or a dictionary.

This happens because the parameters are handled by the library internally as lists and some of Python DB drivers accept it, but e.g. pymssql - not.

[amochin]

I'm switching internal handling of query parameters from lists to tuples.
Apparently, using tuples is actually the default and recommended way, which should be supported by most of python DB drivers.

Handling the data type internally is better than letting the user decide it, because the latter option would be too complicated. Also transferring tests and keywords between different databases would become difficult.

From the user perspective there are no changes.
The parameters in Robot Framework are still to be formed as lists - they're converted to tuples automatically when calling the keywords.

If in future we found a DB driver which accepts lists only, a special handling could be added.