Keep foam in sync with file system (#349)

* added common code from vscode repo

lots of good utility functions and objects, especially around lifecycle and event management

* added datastore and logger services

* refactored bootstrap to consolidate behavior in foam-core

* tags treeview now updates when files are saved

* updated node engine version to match vscode's

* using new event model for foam graph events

.github/workflows/foam-cli.yml

@@ -14,7 +14,8 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1
-
+        with:
+          node-version: '12'
       - name: Install dependencies
         run: yarn
 

.github/workflows/foam-core.yml

@@ -14,6 +14,8 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1
+        with:
+          node-version: '12'
 
       - name: Install dependencies
         run: yarn

.github/workflows/foam-vscode.yml

@@ -14,6 +14,8 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1
+        with:
+          node-version: '12'
 
       - name: Install dependencies
         run: yarn