Refactor devextra.c to use prepared statements

[sean-gilliam]

Right now devextra.c uses several hard coded SQL queries that are vulnerable to SQL injection.

We need to convert those queries to use prepared statements.

Example: (https://github.com/rezalas/riftshadow/blob/master/code/devextra.c#L171-L172)

void do_listoffer(CHAR_DATA *ch, char *argument)
{
...
	sprintf(query,"SELECT * FROM offerings WHERE deity = \"%s\" %s ORDER BY time ASC",
		ch->true_name, autol ? "AND status = 0" : "");
... more logic ...
}