Adds support for tests and benchmarks via Vcpkg features

Enables building unit tests using GTest and benchmarks using Benchmark,
through Vcpkg features.

Adds `tests` and `benchmark` features to `vcpkg.json`,
and adds corresponding CMake logic to control their build based on
Vcpkg manifest features.

CMakeLists.txt

@@ -29,11 +29,16 @@ if (CMAKE_TOOLCHAIN_FILE AND VCPKG_MANIFEST_FEATURES)
             set(OMATH_IMGUI_INTEGRATION ON)
         elseif (omath_feature STREQUAL "avx2")
             set(OMATH_USE_AVX2 ${COMPILER_SUPPORTS_AVX2})
-        else()
+        elseif (omath_feature STREQUAL "tests")
+            set(OMATH_BUILD_TESTS ON)
+        elseif (omath_feature STREQUAL "benchmark")
+            set(OMATH_BUILD_BENCHMARK ON)
+        else ()
             message(WARNING "[${PROJECT_NAME}]: UNKNOWN VCPKG LIBRARY FEATURE CALLED \"${omath_feature}\" ")
         endif ()
     endforeach ()
 endif ()
+
 if (OMATH_USE_AVX2 AND NOT COMPILER_SUPPORTS_AVX2)
     message(WARNING "OMATH_USE_AVX2 requested, but compiler/target does not support AVX2. Disabling.")
     set(OMATH_USE_AVX2 OFF CACHE BOOL "Omath will use AVX2 to boost performance" FORCE)

vcpkg.json

@@ -14,7 +14,6 @@
       "name": "vcpkg-cmake-config",
       "host": true
     }
-
   ],
   "features": {
     "avx2": {
@@ -26,6 +25,18 @@
       "dependencies": [
         "imgui"
       ]
+    },
+    "tests": {
+      "description": "Build unit-tests using GTest",
+      "dependencies": [
+        "gtest"
+      ]
+    },
+    "benchmark": {
+      "description": "Build benchmarks",
+      "dependencies": [
+        "benchmark"
+      ]
     }
   }
 }