[PHPBB3-9582] Missing MSSQL native driver case statements

A few case 'mssqlnative': statements are missing where DB specific SQL is used.

Progress

1.	Advanced Search is inaccessible using the mssqlnative DBAL	Unverified Fix	Chris Smith [X] (Inactive)
2.	Two debug notices are displayed when setting a custom profile field though the UCP using the mssqlnative DBAL	Unverified Fix	Chris Smith [X] (Inactive)
3.	Reported messages are not assigned the default report reason when a reason is removed from the ACP using the mssqlnative DBAL	Unverified Fix	Chris Smith [X] (Inactive)
4.	It is impossible to create a custom profile field using the mssqlnative DBAL	Unverified Fix	Chris Smith [X] (Inactive)
5.	MSSQL native backups cannot be restored	Unverified Fix	Chris Smith [X] (Inactive)