Add Global CMake Build and OSS Tests (#1217)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1217

This updates the CMake build present for being able to share options, fixing up flags, etc. A GTest build is added as well, along with a script and VSCode debug target so that OSS contributors can very easily run and debug tests on any OS.

Note that this isn't completely done (need to revise Windows, Mac, documentation), but should be finished enough otherwise for review.

Changelog: [Internal]

Reviewed By: cortinico

Differential Revision: D42406686

fbshipit-source-id: 95e7ba5e4751c496a171785490e85cf0097fa839

.github/actions/install-ninja/action.yml

@@ -0,0 +1,14 @@
+name: Install Ninja
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install ninja (Linux)
+      if: ${{ runner.os == 'Linux' }}
+      shell: bash
+      run: sudo apt-get install -y ninja-build
+
+    - name: Install ninja (Windows)
+      if: ${{ runner.os == 'Windows' }}
+      shell: powershell
+      run: choco install ninja

.github/actions/setup-cpp/action.yml

@@ -0,0 +1,12 @@
+name: Setup C++ envirionment
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install Ninja
+      if: ${{ runner.os != 'Windows' }}
+      uses: ./.github/actions/install-ninja
+
+    - name: Setup VS Developer Command Prompt
+      if: ${{ runner.os == 'Windows' }}
+      uses: ilammy/msvc-dev-cmd@v1

.github/actions/setup-js/action.yml

@@ -11,15 +11,8 @@ runs:
     - name: Install emsdk
       uses: ./.github/actions/install-emsdk
 
-    - name: Install ninja (Linux)
-      if: ${{ runner.os == 'Linux' }}
-      shell: bash
-      run: sudo apt-get install -y ninja-build
-
-    - name: Install ninja (Windows)
-      if: ${{ runner.os == 'Windows' }}
-      shell: powershell
-      run: choco install ninja
+    - name: Install Ninja
+      uses: ./.github/actions/install-ninja
 
     - name: yarn install
       shell: bash