MB-21
refactoring of the servers table; json is replaced by text and converted
all required fields to text.
revisited update and delete server stored procedures and refactored the
code to support the requirements (validation of the
user/provider/account) and adjusted the code accordingly.
added a new function is_server_valid to check if the provided server
exists and is valid.
i'll have to continue refactoring the code. i still havelist_servers ad
get_server.