Fix Compiler Warnings - Zero Hour + Tools - Level "Wall" warnings

[Mauller]

Related to #482 as a sub task.

Dependent on #505 being completed first to decrease number of warnings shown.

Fix all Wall Level compiler warnings in Zero Hour + Tools for the Vs22 build.
Wall level warnings include Level 4 warnings and some extra warnings.

Only Fix warnings that won't change behaviour or break VC6 compatability.