Small Warnings Refactor (#4477)

* Disable all warnings, even in release, on the `src` directory.
Resolve math macro duplication warnings.

* Suppress LUS warnings.

* Modify it to utilize a variable that defaults on but can be specified in command line to disable it.
Prevet total compile option overwrite for LUS.

* Remove unnecessary unset and cache parameters.

* Document warnings flag in BUILDING.md

docs/BUILDING.md

@@ -31,6 +31,7 @@ cd Shipwright
 
 # Setup cmake project
 # Add `-DCMAKE_BUILD_TYPE:STRING=Release` if you're packaging
+# Add `-DSUPPRESS_WARNINGS=0` to prevent suppression of warnings from LUS and decomp (src) files. set to 1 to re-enable suppression
 & 'C:\Program Files\CMake\bin\cmake' -S . -B "build/x64" -G "Visual Studio 17 2022" -T v143 -A x64
 
 # Generate soh.otr
@@ -133,6 +134,7 @@ git submodule update --init
 
 # Generate Ninja project
 # Add `-DCMAKE_BUILD_TYPE:STRING=Release` if you're packaging
+# Add `-DSUPPRESS_WARNINGS=0` to prevent suppression of warnings from LUS and decomp (src) files. set to 1 to re-enable suppression
 # Add `-DPython3_EXECUTABLE=$(which python3)` if you are using non-standard Python installations such as PyEnv
 cmake -H. -Bbuild-cmake -GNinja
 
@@ -187,6 +189,7 @@ git submodule update --init
 
 # Generate Ninja project
 # Add `-DCMAKE_BUILD_TYPE:STRING=Release` if you're packaging
+# Add `-DSUPPRESS_WARNINGS=0` to prevent suppression of warnings from LUS and decomp (src) files. set to 1 to re-enable suppression
 cmake -H. -Bbuild-cmake -GNinja
 
 # Generate soh.otr