Move desktop-related code to "desktop" subfolder (#872)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/872
Move all the JS code related to desktop app to "desktop" subfolder.

The structure of "desktop" folder:
- `src` - JS code of Flipper desktop app executing in Electron Renderer (Chrome) process. This folder also contains all the Flipper plugins in subfolder "src/plugins".
- `static` - JS code of Flipper desktop app bootstrapping executing in Electron Main (Node.js) process
- `pkg` - Flipper packaging lib and CLI tool
- `doctor` - Flipper diagnostics lib and CLI tool
- `scripts` - Build scripts for Flipper desktop app
- `headless` - Headless version of Flipper app
- `headless-tests` - Integration tests running agains Flipper headless version

Reviewed By: passy

Differential Revision: D20249304

fbshipit-source-id: 9a51c63b51b92b758a02fc8ebf7d3d116770efe9

.github/workflows/nodejs-doctor.yml

@@ -7,17 +7,20 @@ jobs:
 
     runs-on: 'ubuntu-latest'
 
+    env:
+      doctor-directory: ./desktop/doctor
+
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-node@v1
       with:
         node-version: '12.x'
     - name: install
-      working-directory: doctor
+      working-directory: ${{env.doctor-directory}}
       run: yarn
     - name: test
-      working-directory: doctor
+      working-directory: ${{env.doctor-directory}}
       run: yarn test
     - name: run
-      working-directory: doctor
+      working-directory: ${{env.doctor-directory}}
       run: yarn run run

.github/workflows/nodejs-pkg.yml

@@ -7,17 +7,20 @@ jobs:
 
     runs-on: ubuntu-latest
 
+    env:
+      pkg-directory: ./desktop/pkg
+
     steps:
     - uses: actions/checkout@v1
     - uses: actions/setup-node@v1
       with:
         node-version: '12.x'
     - name: install
-      working-directory: pkg
+      working-directory: ${{env.pkg-directory}}
       run: yarn
     - name: test
-      working-directory: pkg
+      working-directory: ${{env.pkg-directory}}
       run: yarn test
     - name: run
-      working-directory: pkg
+      working-directory: ${{env.pkg-directory}}
       run: bin/run

.github/workflows/nodejs.yml

@@ -7,6 +7,9 @@ jobs:
 
     runs-on: ${{ matrix.os }}
 
+    env:
+      desktop-directory: ./desktop    
+
     strategy:
       matrix:
         node-version: [12.x]
@@ -20,19 +23,25 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - name: yarn install
       run: yarn
+      working-directory: ${{env.desktop-directory}}
     - name: lint
       run: yarn lint
+      working-directory: ${{env.desktop-directory}}
     - name: test
       run: yarn test
+      working-directory: ${{env.desktop-directory}}
     - name: build linux
       if: matrix.os == 'ubuntu-latest'
       run: yarn build --linux
+      working-directory: ${{env.desktop-directory}}
     - name: build macos
       if: matrix.os == 'macos-latest'
       run: yarn build --mac --mac-dmg
+      working-directory: ${{env.desktop-directory}}
     - name: build windows
       if: matrix.os == 'windows-latest'
       run: yarn build --win
+      working-directory: ${{env.desktop-directory}}
     - name: upload linux artifact
       uses: actions/upload-artifact@v1
       if: matrix.os == 'ubuntu-latest'