refactor checkCountAndReduceRecordsLimit and bugfix to_many_through_sql + generic associations

[coeit]

Refactor the resolver function checkCountAndReduceRecordsLimit to use a helper function.

This includes:

• move recordLimit reduction and conditional error generation into helper
• leave current resolver function, but make it invoke the above helper
• rename arg query to resolverName
• in generic associations and the hasManyThroughShortAndRememberableNameSql.. (to_many_through_sql_cross_table) do the count in the respective resolver and then invoke the above helper.

Fix the to_many_through_sql_cross_table and generic_to_<many/one> fieldResolvers

[coeit]

• checkCountAndReduceRecordsLimit now gets the model name as parameter to use the correct countRecords function even when called from a fieldResolver.
• actual reduction and check moved to helper.
• fix to_many_through_sql_cross_table + generic_to_<one/many fieldResolvers to correctly use the new design

commit (templates): d75602d078ba1085b310d3d1fbc778112483ec7e

commit (tests) 1f4bd496b141966341fc99699e732b184f40da4e